ABSTRACTResults of surgical treatment in different types of cholesteatoma were analyzed in 431 chronic ears. Mean follow-up period was 6.9 years. The total recurrence rate (including both residual and recurrent cholesteatoma) was 8.6 percent. The recurrence rate was lowest (7.4%) in attic cholesteatoma and highest (10.0%) in pars tensa retraction cholesteatoma. The great majority (98%) of the operations were one-stage procedures. Canal wall down mastoidectomy was the procedure in 297 cases, with a recurrence rate of 7.7 percent; canal wall up mastoidectomy, in 86 cases, yielded a recurrence rate of 9.3 percent, and in 48 ears the cholesteatoma was removed by a transcanal procedure without mastoidectomy, giving a recurrence rate of 12.5 percent. Hearing results in attic and sinus cholesteatoma were significantly better than in pars tensa retraction cholesteatoma. Of the whole series, hearing improved in 36 percent and deteriorated in 28 percent. It is concluded that surgery should be individualized according to site and size of the cholesteatoma, but all large cholesteatomas require canal wall down procedure to avoid recurrence.