This report describes 154 patients treated with cryosurgery for cervical intra-epithelial neoplasia (CIN) over a 3-year period. Standard colposcopic criteria were used to select patients for conservative primary treatment. Treatment failed in 12.5% of 112 patients treated for CIN I (mild dysplasia) and II (moderate dysplasia). Of 42 patients treated for CIN III (severe dysplasia/carcinoma in situ) 45.2% showed persistence of the lesion after primary cryosurgery A second course of treatment resulted in a 98% cure rate for patients with CIN I and II and an 85.7% rate for patients with CIN III. However, 14.3% of patients with CIN III required alternative management after further cryosurgery. Because of this experience the treatment of CIN III has been reviewed at this clinic.