PFI may stand for: Pay for inclusion (paid inclusion), charge by a search engine to include a Web site in its index Pellet Fuels Institute, trade association of the wood pellet fuel industry Percy FitzPatrick Institute of African Ornithology Performance Freediving International, a freediving organization PF International Kart Circuit, a kart circuit in England Popular Front of India, an Islamist organisation in India Port fuel injection (indirect injection), a type of fuel injection used in automobiles Practical Farmers of Iowa, an agriculture NGO in Iowa Pre-flight inspection, of an aircraft Private finance initiative, a way of funding public sector projects with private capital The Prize Fighter Inferno, a musical project of Coheed and Cambria frontman Claudio Sanchez Pro forma invoice, a billing document that is not a demand for payment but gives information about a shipment PFI Convention (Convention on the protection of the European Communities' financial interests), a multilateral EU treaty on fraud Perspektivnyi Frontovoy Istrebitel ("Perspective Frontline Fighter"), Soviet military aircraft; see Post-PFI Soviet/Russian aircraft projects PFIs, or Pharmaceutical Formulation Intermediates, a pharmaceutical term Press Freedom Index