Four patients with Apert's acrocephalosyndactyly were found to have congenital maximum conductive hearing losses. A congenitally fixed stapes footplate and perilymph gusher, suggesting abnormally patent cochlear aqueduct, was found in the ear of one patient, whose mother also had the syndrome. In another young adult Negro patient with stable, long-term hearing loss, middle ear impedance studies were consistent with ossicular fixation. In the fourth patient, a young child, the hearing loss was believed to be present since early life, and the eardrums were normal. The classic overt physical findings of this disorder and occult findings that may be associated are reviewed. Congenital stapes fixation is believed to be a frequent finding in this disorder and should be sought in all patients bearing the stigmata of acrocephalosyndactyly.