Thirty-three patients with perianal Bowen's disease were treated at the Cleveland Clinic Foundation from 1954 to 1986. Twenty-one patients were women and 12 were men, ranging in age from 30 to 69 years (mean, 48 years). Twenty patients (61 percent) presented with symptomatic perianal disease, while 13 patients (39 percent) were noted as having perianal Bowen's disease upon pathologic examination of routine hemorrhoidectomy specimens. Ten of the patients (30 percent) had prior histories of unrelated cancer. Twenty-seven patients were managed by wide local excision, three patients by simple excision, three patients by fulguration, and one patient by an abdominoperineal resection. During a follow-up period averaging 3.7 years (range, 0.3 to 10 years), one patient developed a new invasive skin cancer while a second patient experienced a recurrence of perianal Bowen's disease. The characteristic gross appearance of this lesion and its failure to respond to conventional therapy should prompt the performance of a biopsy, which readily establishes the diagnosis. This experience confirms that wide local excision is adequate therapy for perianal Bowen's disease and that close clinical follow-up is necessary to identify disease recurrence or the development of a malignancy.