A retrospective study of the complications of cone biopsy showed that among 9 15 women examined between t h e years 1976 and 1982, 121 (13%) had primary or secondary haemorrhage, 153 (17%) cervical stenosis and 39 (4%) subsequent infertility or an abnormal pregnancy. Cervical stenosis was commonest among women who had had long cones removed. Stenosis occurred more often in the group of women who had been assessed by colposcopy before operation but this was due t o the fact that prior colposcopy selected a favourable group of patients with lesions of limited extent that were susceptible to treatment by local destructive therapy, so that prior colposcopic assessment resulted in the removal of longer cones.