Abstract Fifteen patients with repetitive hydatidiform mole were followed at the New England Trophoblastic Disease Center between 1965–1988. The medical records were examined to determine the patients' age, gravidity, parity, clinical presentation, development of post-molar tumor, and subsequent pregnancy experience. Each molar tissue was reviewed pathologically. Seven patients had repetitive complete hydatidiform mole and three developed persistent post-molar disease after their later mole. Five patients had an initial complete hydatidiform mole followed by a partial hydatidiform mole; two developed persistent post-molar disease after the partial mole. One patient had an initial partial hydatidiform mole followed by a complete hydatidiform mole and required chemotherapy after her complete mole. Two patients had repetitive partial hydatidiform mole, and neither developed post-molar disease. Four of the patients with repetitive mole later achieved a normal viable pregnancy. Molar pregnancies must be categorized as either complete or partial to provide meaningful data concerning repetitive hydatidiform mole.