Topical 5-fluorouracil (5-FU) has proven effective in epidermoid cancers of the head and neck. Its effectiveness was correlated with the ability of the patient''s immunologic system to recognize new antigens. In this study, 8 patients with carcinoma in situ of the vulva were evaluated and treated with topical 5-FU. Evaluation and followup was completed and the literature was reviewed. The overall treatment response rate was 75%. Followup to date was 3-39 mo. Thirty-five cases were reviewed from this series and the literature with a similar outcome.