Established in 1849 by cousins Charles Pfizer and Charles Erhart in Brooklyn, New York; developed products through intensive pharmaceutical research during the second half of the 20th century; acquired Warner-Lambert (2000) and Pharmacia (2003).

Ranked one of the highest pharmaceutical manufacturers in the world (based on sales-2008) producing drugs such as: Lipitor (atorvastatin, used to lower blood cholesterol); the neuropathic pain/fibromyalgia drug Lyrica (pregabalin); the oral antifungal medication Diflucan (fluconazole), the long-acting antibiotic Zithromax (azithromycin), and the erectile dysfunction drug Viagra; they now also specialise in veterinary prescription medicines having merged with Wyeth's Fort Dodge Animal Health. They now have organisations throughout the world.