Although testes cancer is the most common malignancy affecting young men, dramatic survival rates are now possible with the development of optimal individualised drug therapy. Human chorionic gonadotropin and alpha-fetoprotein are important tumour markers associated with testes cancer, and can provide essential information about prognosis and treatment efficacy. For treatment purposes, testicular germ-cell malignancies are broadly classified as seminomatous or non-seminomatous. Early stage seminomas are treated with radiotherapy, while more advanced disease requires systemic chemotherapy. Stage I nonseminoma patients can now be offered the option of retroperitoneal lymph node dissection (RPLND) or close clinical observation, while patients with stage II or III nonseminoma should generally be treated with chemotherapy. The dramatic survival rates now apparent with chemotherapy are due in large part to the introduction of cisplatin (cisplatinum II)-based chemotherapy and to the optimisation of therapy based on pretreatment risk analysis. The most common chemotherapeutic regimen for standard risk patients includes cisplatin and etoposide (VP 16213) and long term disease-free survival rates exceed 80%. A subset of poor risk patients with significantly reduced survival can be defined. These patients, and patients with relapsed or refractory disease, should receive more aggressive regimens, and ifosfamide (isophosphamide) is proving to be a particularly promising new agent in this regard. High-dose carboplatin with autologous bone marrow rescue is another encouraging alternative currently being investigated for these patients. Chemotherapy, despite substantial effectiveness, is not without toxicity, which consists primarily of myelosuppression, nausea and emesis, and renal toxicity. With careful monitoring and prophylaxis, however, these toxicities can generally be ameliorated or avoided.