Recent reports of isolation of bacteria from effusions of the middle ear taken from asymptomatic children have suggested a possible role for persistent bacterial infection in the etiology of prolonged effusions. To investigate the significance of anaerobic bacteria in such effusions, we obtained 51 samples of middle ear effusion (MEE) from 30 children. After careful cleansing of the tympanic membrane with 70% alcohol, we performed tympanocentesis prior to performing a myringotomy. Fastidious bacteriologic methods failed to yield a single anaerobic isolate from any of these specimens. We conclude that anaerobic infection of MEE is exceedingly uncommon.