Stapes surgery for fixed footplate associated with X-linked congenital mixed hearing loss usually results in a "gusher" and severe worsening of hearing. Four patients with X-linked deafness were diagnosed by the characteristic temporal bone computed tomography (CT) findings of enlarged internal auditory canal, hypoplasia of the cochlear base, absent bony modiolus, abnormal vestibular aqueduct, and enlarged labyrinthine facial nerve canal. Three patients were scanned after stapes surgery resulted in a gusher and, in two patients, severe worsening of their hearing loss. Stapes fenestration in the other patient was avoided by CT recognition of the dysplasia. The authors believe that young males presenting with congenital mixed hearing loss should be studied with temporal bone CT prior to middle ear exploration.