The following is a timeline of the Syrian civil war from September to December 2012. Information about aggregated casualty counts is found at Casualties of the Syrian Civil War.

September 2012

3 September

By the end of the day, the LCC reported over 250 people had been killed, over 60 in the Aleppo province and over 60 in the Daraa province due to bombardment by warplanes.

4 September

By the end of the day, the LCC reported 155 people were killed, including 80 in the Damascus suburbs.

5 September Syrian activists reported heavy fighting between Rebel forces and the Syrian Army in Aleppo multiple suburbs of Damascus. The Syrian Observatory for Human Rights said 6 bodies had been found in Tadamon showing signs of having been tortured. The LCC reported that 260 people were killed by the end of the day, including 115 in Aleppo and 67 in the Damascus suburbs.

6 September 159 people were killed by the end of the day, according to the LCC, including 88 in the Damascus suburbs. The Syrian Army recaptured the town of Tell Shihab from rebels.

7 September By evening the LCC reported that 140 people were killed, including 44 in the Damascus suburbs and 28 in Aleppo.

Iraqi security and medical officials said a 4-year-old girl was killed, and 4 others injured, in the Iraqi town of al-Qaim, by mortar fire from Abu Kamal, just across the Syrian border. The anti-government Syrian Observatory for Human Rights said Albu Kamal had been being shelled that day.

8 September The LCC reported 178 people killed across Syria, including 89 in Aleppo. On 9 September, The LCC reported 160 killed across Syria, including 40 in the Damascus suburbs.

9 September A car bomb exploded at the Saad al-Ansari district of Aleppo, targeting al-Hayat hospital near the 7 April Stadium. 32 were killed and at least 64 people were injured as a result of the blast.Syria raises death toll in Aleppo blast to 30. Daily Star, 10 September 2012

11 September By the end of the day the LCC reported 130 people killed, including 43 in Aleppo and 34 in the Damascus suburbs.

12 September By the end of the day the LCC reported 173 people killed, including 67 in Aleppo.

13 September At least 11 people were killed in an airstrike in Aleppo. New UN envoy Lakhdar Brahimi arrives in Damascus. By the end of the day the LCC reported 165 people were killed, including 57 in the Damascus suburbs. Al Qaeda urged all Islamists to support the rebellion against the Syrian government.

14 September Eight Syrians were arrested by the Lebanese Army while travelling in a truck containing a large quantity of weapons. Yousef Assad, a high ranking Syrian Air Force officer and relative of Syrian President Bashar al-Assad, announced his defection to the opposition with an online video. By the end of the day the LCC reported 165 people killed across Syria, including 66 in the Damascus suburbs.

15 September By the end of the day the LCC reported 164 civilians killed across Syria, including 67 in the Damascus suburbs.

16 September A German Der Spiegel reported that Syria has tested ordnance capable of carrying chemical weapons in desert near Aleppo at the end of August. Iran's Revolutionary Guards commander Mohammad Ali Jafari admits that Iran's elite forces are operating in Syria. The LCC reported 167 civilians killed, including 60 in the Damascus suburbs and 50 in Aleppo.

17 September By the end of the day the LCC reported 147 civilians killed, including 50 in the Damascus suburbs.

18 September By the end of the day the LCC reported 160 civilians killed, including 67 in the Damascus suburbs.

19 September Opposition forces seized a border crossing between Syria and Turkey in Tal Abyad District, Raqqa Governorate. By the end of the day the LCC reported 150 civilians killed, including 72 in the Damascus suburbs.

20 September By the end of the day, over 250 civilians were killed, including over 71 in Raqqa when a warplane bombed a petrol station, according to the LCC. A Syrian Airbus A320 collides with a Syrian Mil Mi-17 helicopter which results in the helicopter crashes and the tail of the passengerplane being damaged.

21 September

98 civilians were reported dead; including 34 in the Damascus Countryside. 17 rebels were slain; with 5 dead in Aleppo including a battalion leader. 32 Syrian soldiers were killed; including a colonel; according to SOHR.. 21 September 2012. Syrian Observatory for Human Rights. Retrieved 23 September 2012. By evening 117 civilians were killed, including 48 in the Damascus suburbs, according to LCC. A Syrian Air Force jet was reported shot down over the northern Syrian town of Atarib in the Idlib province.

22 September Activists reported that over 180 people were killed in Syria, mostly in the Damascus suburbs and Aleppo. Col. Riad al-Asaad announced on video that the FSA had moved its command centre into an undisclosed location inside Syrian territory from Turkey in light of rebel gains. Andrew Simmons, reporting for Al Jazeera in Akcakale, stated that the FSA is still dependent on Turkish supply lines and that rebels have only taken territory 5 km deep into Syria. By the end of the day the LCC reported that 220 civilians were killed, including 66 in the Damascus suburbs.

23 September

Nearly 80 percent of towns and villages along the Turkish border are outside the control of Damascus, according to the Syrian Observatory for Human Rights. By evening 85 civilians were killed, including 22 in the Damascus suburbs, according to the LCC.

24 September By the end of the day the LCC reported that 123 civilians were killed, including 42 in Aleppo and 37 in the Damascus suburbs.

25 September By evening the end of the day the LCC reported that 148 civilians were killed, including 44 in the Damascus suburbs.

26 September

26 September was the single bloodiest day since the beginning of the uprising, up to this point. SOHR reported over 300 deaths; similarly LCC reported over 300 civilian deaths, including 162 in the Damascus suburbs, among which were 107 in a massacre in Thiabieh.. 26 September 2012. Syrian Observatory for Human Rights. Retrieved 30 September 2012. The Press TV correspondent Maya Nasser was killed by sniper fire while covering from the scene of twin bomb blasts in Damascus.

27 September Virtual warfare took part in Syria when Syria military send text messages to rebels: "Game over."

By the end of the day the LCC reported 133 civilians killed, including 35 in the Damascus suburbs. SOHR reported the deaths of 108 civilians (including at least 11 children), 14 rebels & 35 soldiers.. 27 September 2012. Syrian Observatory for Human Rights. Retrieved 30 September 2012. A Kurdish fighter was killed in clashes between the Kurdish Popular Defence Committees & rebels of the Salah al-Din battalion in Hama.

28 September The United Nations Human Rights Council condemns Syria and extends war crimes inquiry. Russia, China and Cuba vote against Arab resolution. According to FSA they launch "decisive battle" in Aleppo. The LCC reported 167 civilians killed, including 57 in Aleppo.

29 September The LCC reported 126 civilians killed by evening, including 64 in the Damascus suburbs.

30 September A militant group fighting President Bashar al-Assad's forces in Syria said in a video posted online on Sunday it had captured five Yemeni army officers sent by their government to help quell the Syrian uprising. By the end of the day 154 civilians were killed, including 76 in the Damascus suburbs.

October 2012

1 October At least 164 people were killed by the end of the day, including 12 children, according to the opposition Local Coordination Committees. More than 30 of these deaths occurred due to aerial shelling by government forces. 42 people were killed in Idlib, including 30 who were killed in a reported massacre in the town of Salqin, the LCC said. 51 were also killed in and around the capital city of Damascus.

2 October The LCC reported that 160 civilians were killed by the end of the day, including 54 in the Damascus suburbs. A Hezbollah commander, Ali Hussein Nasif, and several other fighters were killed in Syria when opposition forces ambushed their convoy near al-Qusayr. This was confirmed by the group.

3 October In Aleppo, three suicide car bombs exploded killing 40 and injuring at least 122 people. A Syrian mortar bomb killed 5 Turkish civilians in the Akçakale district; Turkey responded with counter-battery fire. The LCC reported over 200 civilians killed by the end of the day, including 67 in the Damascus suburbs.

4 October By the end of the day the LCC reported 120 civilians killed, including 52 in the Damascus suburbs. Turkey's parliament approved further military action against Syria after a second artillery exchange across the border.

5 October Syrian rebels say they captured an air defense base with a cache of missiles outside Damascus. Included what appeared to be part of a surface-air-missile. It is unlikely that rebels have the ability to fire the missile but they might be able to use the explosives to make improvised bombs. Turkey moved tanks and anti-aircraft artillery into Akçakale after a third Syrian mortar attack across the border. The LCC reported 127 civilians killed, including 36 in Aleppo and 28 in the Damascus suburbs.

6 October Turkey and Syria exchanged artillery fire across the border for the fourth time. Syrian rebels captured the village of Khirbet al-Joz, Jisr al-Shughur District, close to the border with Turkey. The government death toll was significantly higher than that of the rebels'.. 6 October 2012. Hurriyet Daily News. Retrieved 6 October 2012. 40 Army soldiers and 9 rebels were killed. The LCC reported 95 civilians and 10 FSA soldiers killed, including 31 people in the Damascus suburbs.

7 October Syria and Turkey exchanged artillery fire for the fifth consecutive day after Syrian mortar bombs hit a grain plant in Akçakale and an uninhabited area of Altınözü. A cousin to Bashar al-Assad, Housam al-Assad has reported been taken hostage by FSA. Syrian scholar and political writer Mohammad Nemr al-Madani was killed under torture while in detention at the state security's Branch 215 in Damascus. A former media aide to President Assad said that the president was planning to flee to Russia "after the regime collapses." LCC reported 121 civilians killed, including 62 in the Damascus suburbs. SOHR reported the deaths of over 93 civilians, at least 41 of which were slain in the Damascus Suburbs. 31 rebels were killed, more than 10 in Homs. 39 soldiers were killed.. 7 October 2012. Syrian Observatory for Human Rights. Retrieved 9 October 2012.

8 October Turkey and Syria exchanged artillery fire for the sixth consecutive day after a Syrian shell landed in Altınözü district. LCC reported that 170 civilians were killed by the end of the day, including 40 in Aleppo and 37 in a mass execution in Maarat al Numaan, Idlib.

9 October

Rebels seized the strategic town of Maarrat al-Nu'man, situated on a highway linking Aleppo to Damascus. LCC reported that 197 civilians were killed by the end of the day, including 65 in the Damascus suburbs and 53 in Aleppo.

10 October Rebel forces halted a Syrian Army attempt to recapture the strategic town of Maarrat al-Nu'man. At least 30 rebels and scores of Syrian government forces died in the fighting. Rebels advanced in other areas, taking over 10 towns and villages in the North. Rebels claimed to fully control territory from the Turkish border to 10–20 km inside Syria. Turkish Air Force F-16s intercepted a Syrian Air Airbus A320, flight RB442 from Moscow to Damascus, in Turkish airspace and forced it to land at Esenboğa International Airport, suspecting it was carrying Russian-made weapons. Inspectors confiscated military communications equipment and items "thought to be missile parts". The LCC reported that by the end of the day 197 civilians were killed.