From 1969 through 1985, 4584 women in the state of New Mexico were diagnosed with carcinoma in situ of the cervix. Of these women, 65.5% underwent hysterectomy while 31.1% had a conservative therapy (primarily conization). Over the 17-year period, there was a steady increase in the percentage of women receiving conservative therapies, from 11.8% in 1969 to 50.3% in 1985. Younger women, unmarried women and American Indian women were more likely to receive conservative therapy. This marked shift in therapeutic approach occurred during a time of apparent controversy as to the optimal treatment for cervical carcinoma in situ, and illustrates a rapid change in surgical practice in the absence of any controlled trials comparing the two major treatment modalities.