Bowen's disease of the anus is usually treated by wide local excision including macroscopic normal areas if random biopsies show dysplasia. Skin grafting will often be necessary, since areas of microscopic dysplasia may be found at a considerable distance from the gross affected site. In this study of 11 patients with Bowen's disease of the anus we report the results of a more conservative approach. All patients were treated by local excision of the gross affected areas only, and none of the patients required skin grafting. Seven patients were followed for a median of 34 months without macroscopic recurrence, including 3 patients with histologically proven dysplasia in the resection margins. Two patients, one with and one without dysplasia in the resection margins, developed recurrence within a year. One patient with an area of invasive carcinoma was first treated by local excision, but required an abdominoperineal excision 3 months later. One patient lost to follow-up had invasive carcinoma after 3 years. It is concluded that a conservative surgical approach in Bowen's disease of the anus is justified, provided the patients are followed closely.