Nine hundred sixty-eight patients with cervical intraepithelial neoplasia (CIN) were evaluated with colposcopy and treated with cryosurgery; 722 had a pretreatment diagnosis of CIN I or II and 246 had CIN III. Of those patients available for 2 follow-up smears, histologically proved persistence of CIN was found in 10% of patients with CIN I and II and 20% of patients with CIN III. Recurrent disease was detected in 3.2 and 3.8%, respectively. No patients had a recurrence after 5 negative Papanicolaou smears. One patient had invasive carcinoma 30 months after treatment. Failure of patients to return for follow-up was a significant problem. When the present results were compared to those published in the literature, cryosurgery was found to be less effective than conization in treating CIN III.