Although virtually 100% of women who develop gestational trophoblastic tumors enter a long-term complete remission, there are many aspects of trophoblastic disease that arouse interest. Epidemiological studies have shown a large geographical variation in the percentage of conceptions that result in a hydatidiform mole and have stimulated studies on the immunological differences of the low and high risk populations. Chromosomal analysis is now complementing the pathological differentiation between complete and partial moles. There is still debate as to which factors are positively associated with the progression of a hydatidiform mole through invasive mole to choriocarcinoma. There are also considerable differences in the proportion of molar patients receiving chemotherapy in different centers. In addition to these topics, this article will review several recently introduced treatment regimens which show improved results with reduced toxicity.