Conclusion. The treatment plan should be adapted in accordance with the individual cause for each patient with external canal cholesteatoma (EACC). Outpatient surgery with eradication of the cholesteatoma and canal reconstruction at an early stage to enable epithelial recovery and migration was proved to be the choice that was effective, low cost, and produced less suffering for the patient to achieve optimal results for most primary EACCs. Objectives. To assess the indications, operation methods, and results of surgery for EACC. Patients and methods. This retrospective case review was conducted in a tertiary referral center, Chi Mei Medical Center, from 1989 to 2007. Outpatient surgery to eradicate diseased canal epithelium and reconstruct a funnel-shaped canal was performed in the cases with primary EACC at an early stage, while inpatient surgery was conducted in the advanced cases. Assessments of cause and outcome were based on the combination of clinical history, physical examination, and radiographic appearance. Results. Clinical records of 45 patients (7 with bilateral lesions) were reviewed; 34 patients were noted with primary EACC and 11 patients with secondary EACC. Surgery was conducted in 42 ears to restore normal epithelial migration. Successful results on an outpatient basis were obtained in most patients.