Controversy exists concerning stapedotomy for patients with small unilateral air-bone gaps. Surgical treatment of otosclerosis involves an opening to the labyrinth and accordingly, a risk of complications, usually vertigo and sensorineural hearing loss and infrequently anacusis. In this paper we present a 33-year-old woman with a small unilateral air-bone gap, who developed bacterial labyrinthitis with meningitis and anacusis three days after stapes surgery. The patient had a stapedotomy with the small fenestra piston prosthesis technique. Due to the potential for serious complications, patients with unilateral otosclerosis and mild hearing loss should be given the possibility to choose between a hearing aid and surgery. Although stapedotomy in the vast majority of interventions is a highly successful procedure and the best method of treatment for otosclerosis if successful, there is a high price to pay in the event of failure.