The development of metastases from germ cell tumours of the testis is studied in terms of its histopathological, ontogenetic, anatomical and evolutive aspects. The treatment of non-seminomatous germ cell tumours and pure seminomas is analysed separately. The prognostic factors defined by the risk of failure of treatment are described and the medical and surgical strategies or combinations of both modalities are proposed for each stage of these cancers. The major points and novelties include: the usual histological polymorphism of these tumours. The markers include alpha-foetoprotein and HCG. Combination chemotherapy, essentially the EBP sequence, is the treatment for non-seminomatous germ cell tumours. In the case of failure, toxic sequences can be used followed by autologous bone marrow transplantation. In the case of persistent lesions (lung, mediastinum, liver, retroperitoneum), salvage surgery may be useful. Metastatic seminomas are treated by radiotherapy and/or chemotherapy, depending on their stage.