Several authors have reported an increased failure rate using cryotherapy when the endocervical clefts or glands were involved in cervical intraepithelial neoplasia. Over a period of 5 years, November 1973 to November 1978, 248 patients with cervical intraepithelial neoplasia (CIN), satisfactory colposcopy, and colposcopically directed biopsy were treated with cryosurgery. Of the 248 patients, 160 patients had adequate follow-up. The failure rate was 16.3% ( 26 160 ). Sixty-three (39.4%) of the 160 patients had gland involvement. Of those patients with gland involvement, there was a failure rate of 27% (17 of 63 patients). The evidence suggests that the presence of gland involvement in patients with CIN adversely affects cure by cryosurgery. The degree of severity of CIN among patients who failed therapy was not a significant factor.