Pharyngitis is one of the most common clinical problems. Its causes are multiple, two of the best known being streptococcal infection and infectious mononucleosis. Group A beta-hemolytic streptococcal infections are the focus of diagnostic and therapeutic efforts aimed at reducing the risk of both suppurative and nonsuppurative complications. Several non-group A infections are important to recognize as sources of pharyngitis. In addition, mycoplasmal and chlamydial pharyngitis may be more prevalent than is realized. The possibility of gonococcal pharyngitis should be given special attention because of the severity of complications. Recurrent pharyngitis is difficult to manage. Except for certain specific indications, tonsilectomy remains an unproven therapeutic approach.