The authors reviewed the records of 50 patients with carcinoma in situ of the vulva seen at the State University of New York at Buffalo affiliated hospitals. Five patients (10%) were found to be immunosuppressed and 12 (24%) had other preinvasive and invasive genital or extragenital neoplasia. Of 43 patients whose symptomatology was available, almost half (46.5%) were asymptomatic. The most common symptom was vulvar itching in 18 (42%), and 32 (65%) patients had white vulvar lesions. Thirteen patients underwent vulvectomy, 23 underwent wide local excision, 8 underwent skinning and skin graft, 3 underwent topical 5-fluorouracil treatment, and 2 underwent CO2 laser treatment. On follow-up there were 6 patients with recurrent and/or persistent disease. Two recurrences followed wide local excision. Topical 5-fluorouracil failed in all 3 patients and CO2 laser failed in 1 of the 2 underwent laser treatment. There were 5 patients with invasive disease. In 3, diagnostic biopsy failed to reveal invasive neoplasia before surgical excision, and invasion was noted after 5-fluorouracil application in one and after CO2 laser treatment in another. All recurrences responded to therapy. In 41 patients followed up for 3 months to 11 years, there were no cancer-related deaths.