In this study cultures of middle ear exudate were obtained from 267 cases of otitis media in infants and children. Pneumococci were found in 34.5%, Hemophilus influenzae in 27%, Group A beta hemolytic streptococci in 1.9%, and pneumococci mixed with hemophilus influenzae in 2.8%. Neisseria, probably Neisseria catarrhalis, were grown in pure culture in 5.2%. Pseudomonas aeruginosa, Staphylococcus hemolyticus (coagulase positive), and Escherichia coli were found in isolated cases. The remaining 27.7% were sterile, these usually being from chronic exudative (secretory) otitis media cases. The incidence of Hemophilus influenzae otitis media found in this study is higher than that reported in previous studies. The finding of Neisseria catarrhalis in exudate from otitis media has been reported only by Gronroos, et al., and observation of the organisms in an intracellular state was not reported. Examination of exudate obtained from recurrences or relapses of acute exudative otitis media often reveals a different organism from that found in previous infections; one cannot assume that an apparent relapse is due to the same organism cultured previously. Most cases of otitis media occur in infants who cannot localize their symptoms, and diagnosis requires careful examination of the ears. Adequate bacteriological studies of exudate from the tympanic cavity require uncontaminated specimens which are best obtained with an apparatus using a needle attached to a collecting trap and a source of negative pressure.