The middle ear and mastoid spaces contain delicate and functionally important structures. Safe cholesteatoma surgery requires mastery of otologic anatomy as well as thorough preoperative investigation. Cholesteatoma can damage otologic structures on its own; however, there is also an opportunity for an iatrogenic complication given the distortion of anatomy by the disease process. This article explores complications that can occur during cholesteatoma surgery, guidance on how to avoid intraoperative complications, and treatment of such complications.