AbstractThe long‐term results of 375 primary mastoidectomy operations for chronic otitis media and chronic mastoiditis are described and discussed. Two‐thirds of these cases were open cavity mastoidectomies and 1/3 closed cavity mastoidectomies. Primary pathology was cholesteatoma in 1/3 and granulation tissue in 2/3 of the cases. The method of reducing the size of the mastoid cavity by sculpturing mastoid cortical bone is most important in avoiding large postoperative cavity problems.Principles and methods are described. Healing (dry ear) is a more important management objective than hearing and, indeed, enhances the prospects of obtaining a long‐term hearing result. Three important phases of controlling mastoid disease (preoperative, operative, and postoperative) are equally stressed. Intact wall tympanomastoidectomy is not recommended in sclerotic mastoids (the majority of our cases) as being unsafe and unnecessary. Revisions, mostly minor, were done in 31% of the cases for a total of 521 procedures. We recommend a one‐stage tympanomastoidectomy. Multiple planned procedures are, in the main, unnecessary and should be avoided to reduce unnecessary hospitalization and expense.