One-hundred thirty-two patients with abnormal Papanicolaou smears of the cervix uteri during pregnancy underwent colposcopic evaluation. Seventy-five patients had biopsies during pregnancy, and 34 patients had colposcopic evaluation without performing any biopsy. Postpartum colposcopic evaluation was performed on 95 patients. In 93 patients of this group, the postpartum cytologic and histologic information obtained was the same or less than that obtained in antepartum evaluation. In only 1 case, antepartum colposcopically guided biopsy at 38 weeks' gestation revealed moderate dysplasia, and postpartum cold conization showed carcinoma in situ. In another case, colposcopic evaluation and biopsy during pregnancy showed mild dysplasia while colposcopic biopsy as well as examination of a hysterectomy specimen taken at 16 months after delivery revealed severe dysplasia. No case of invasive carcinoma was missed during pregnancy. The results of this study, in support of previous reports, show that colposcopic evaluation is a simple, safe, and accurate method of investigating abnormal Papanicolaou smears during pregnancy.