Acute otitis media is overdiagnosed. Symptoms are neither sensitive nor specific for the diagnosis of otitis media; fever and ear pain are present in only one half of patients. Undue reliance on one feature--redness of the tympanic membrane--and failure to assess tympanic membrane mobility with pneumatic otoscopy contribute to inaccurate diagnoses. Adequate visualization of the tympanic membrane is often impaired by low light output from old otoscope bulbs and blockage of the ear canal by cerumen. Distinguishing acute otitis media from otitis media with effusion is clinically important because antibiotics are seldom indicated for the latter condition. A key differentiating feature is the position of the tympanic membrane: it is usually bulging in acute otitis media and in a neutral position or a retracted position in otitis media with effusion. Tympanometry and acoustic reflectometry can be useful adjunctive tools to confirm the presence of fluid in the middle ear. Selective use of tympanocentesis in cases of refractory or recurrent middle ear disease can help guide appropriate therapy and avoid unnecessary medical or surgical interventions.