The results of 70 middle ear reconstructions using either total or partial ossicular replacement prostheses are presented, the mean observation period being 45 months. Twenty-seven of the prostheses (39%) were extruded, this occurring as late as 72 months after surgery, and four (6%) were removed at reoperation. The surgical results when assessed by the magnitude of the air-bone gap are comparable to those of other series in the literature. However, postoperative air conduction thresholds remained high, and 23% of the patients are using hearing aids. The average air-bone gap for the frequencies 0.5, 1, and 2 kHz does not provide information on patients' everyday hearing level, and should no longer be employed as an index for assessing the functional results of middle ear surgery.