This is an update of the original review that was published in The Cochrane Database of Systematic Reviews, 2009, Issue 2. Gestational trophoblastic neoplasia (GTN) are malignant disorders of the placenta that include invasive hydatidiform mole, choriocarcinoma, placental-site trophoblastic tumour (PSTT) and epithelioid trophoblastic tumour (ETT). Choriocarcinoma and invasive hydatidiform mole respond well to chemotherapy: low-risk tumours are treated with single-agent chemotherapy (e.g. methotrexate or actinomycin D), whereas high-risk tumours are treated with combination chemotherapy (e.g. EMA/CO (etoposide, methotrexate, actinomycin D, cyclophosphamide and vincristine)). Various drug combinations may be used for high-risk tumours; however, the comparative efficacy and safety of these regimens is not clear.