Trophoblastic diseases include benign pre-tumor entities (hydatidiform moles) and malignancies called gestational trophoblastic tumors. Most of the latter arise after a hydatidiform mole and are referred to as post-molar trophoblastic tumors. Their diagnosis relies on elevated human chorionic gonadotrophin (hCG) levels following a mole, without the need for histological confirmation. Other forms, including choriocarcinoma, placental site trophoblastic tumor (PSTT), and epithelioid trophoblastic tumor (ETT), require histology; notably, PSTT and ETT are relatively resistant to chemotherapy and usually necessitate surgery. The management of post-molar tumors and choriocarcinomas is guided by the International Federation of Gynecology and Obstetrics prognostic score: low-risk cases are treated with monochemotherapy, whereas high-risk forms by polychemotherapy. In refractory disease, immune checkpoint inhibitors represent an emerging option. Gestational choriocarcinoma is characterized by its marked malignancy, aggressiveness, and ability to spread to the mother and fetus. Diagnosis is based on histology combined with abnormally elevated circulating or urinary levels of hCG. Neonatal choriocarcinoma, resulting from transplacental transmission, is exceptionally rare yet life-threatening. It typically manifests early in life, with hemorrhagic visceral metastases. Management, although non-standardized, generally involves platinum-based chemotherapy followed by possible surgical removal of residual lesions. Therapeutic intervention must be prompt and adapted to neonatal pharmacokinetics, while addressing the significant risk of hemorrhagic complications. This review summarizes current knowledges on the diagnosis and treatment of gestational trophoblastic diseases, with particular emphasis on gestational choriocarcinoma and its neonatal counterpart.