Colposcopy was used to examine 401 pregnant patients with cytologic or clinical abnormalities of the cervix to determine if routine biopsy could be safely omitted except where the colposcopic impression was one of possible invasive carcinoma. A comparison of the antepartum colposcopic impressions with the postpartum histologic diagnosis revealed agreement to within one degree in 87% of patients, with 3% of patients showing a more advanced lesion than that anticipated. Only 2% of patients showed a progression of cytologic abnormalities at postpartum examination; 39% showed marked improvement. Four of nine patients with invasive carcinoma were diagnosed at antepartum colposcopy, with an additional two patients recognized as having invasive cancer at the postpartum colposcopic examination. The omission of routine biopsy is less than ideal if only one antepartum colposcopy is performed, since a considerable period of time may elapse before the patient is seen again postpartum. Those situations in which it may be omitted, together with guidelines for the management of pregnant patients with abnormal cervical cytologic findings, are presented.