Charts of 145 patients with unilateral chronic otitis media were reviewed for evidence of sensorineural hearing loss, defined as the difference in preoperative bone conduction thresholds between diseased and normal contralateral ears. Mean bone conduction differences were small but statistically significant, ranging from 9.2dB in tympanoplasy to 16.2dB in tympanomastoidectomy cases across the frequencies. Duration of the disease, size of the perforation of drum & sex did not have any differences in bone conduction. But significant relationships were found between sensorineural loss and the presence of purulent middle ear discharge, acquired cholesteatoma in the middle ear and large perforation of the drum with cholesteatoma.