Thirty patients with abnormal cervical cytology had a colposcopy during pregnancy. Their management during and after pregnancy is described and supports the contention that the introduction of a colposcopy service safely permits a greater selectivity in management without recourse to operative intervention during pregnancy. In one patient a preclinical invasive squamous carcinoma of the cervix was diagnosed by colposcopy, and in another three, in whom colposcopy could not exclude the presence of invasion, a wedge biopsy under anaesthesia and two punch biopsies without anaesthesia had to be performed. In the remaining 26 patients, the possibility of invasion could be excluded by colposcopy and further treatment deferred until after pregnancy.