With recent progress in chemotherapy, the prognosis of patients with trophoblastic disease has greatly improved, but the remission rate of patients with choriocarcinoma remains unfavorable. To improve the prognosis of these patients, early detection and early treatment are essential. Under the leadership of the Committee of Trophoblastic Disease of the Japan Society of Obstetrics and Gynecology, regional registries of trophoblastic disease were started in 1974. By 1982 14 prefectures with a total population of 46,893,620 were included in the registry. The early detection and treatment and follow-up made possible by the registry in addition to the introduction of advanced chemotherapy may be responsible for a rapidly decreasing trend in the death rate from this disease.