Following hydatidiform mole, women are at increased risk of persistent gestational trophoblastic neoplasia (pGTN) and are therefore monitored using serum human chorionic gonadotrophin (hCG) concentration measurements. We retrospectively evaluated the policy of extended (2 year) follow up for women with hCG concentrations returning to normal >56 days after evacuation. Of 6701 women registered for hCG follow up, 422 (6%) developed pGTN, 412 (98%) of these women presented within 6 months after evacuation. Three developed pGTN at 402, 677 and 1267 days after evacuation following spontaneous normalisation of hCG levels. Only one woman was detected by routine extended follow up. Prolonged surveillance after molar pregnancy causes significant anxiety and is not cost-effective. Therefore, the current revised protocol comprises hCG follow up for 6 months after spontaneous return of hCG levels to normal for all women.