In mature and immature teratoma the treatment is surgical. The risk of recurrence can be estimated from the parameters primary site (with the coccygeal tumors being most at risk), histological grade of immaturity and completeness of the primary resection including the adjacent organ of origin (coccyx, ovary, testis etc.). In case of a microscopically complete tumor resection there is no role for adjuvant chemo- or radiotherapy irrespective of the histological grade of immaturity. Malignant germ-cell tumors (GCT) account for 2.9% of all malignant tumors of children younger than 15 years of age. More than half of the tumors occur at extragonadal sites such as the ovaries (26%), the coccygeal region (24%), the testes (18%) and the brain (18%) represent then primary sites. In patients with extensive tumor growth, metastatic disease or secreting intracranial tumors a delayed tumor resection after preoperative chemotherapy is preferable. In these patients malignant non-seminomatous GCT may be diagnosed clinically due to the increased serum or cerebrospinal fluid levels of the tumor markers AFP and/or beta-HCG. Current risk adapted treatment protocols containing cisplatinum allow long-term remissions in about 80% including patients with bulky or metastatic tumors. In the cisplatinum era the prognostic factors like histology, primary site of the tumor and initial tumor stage have partly lost their former impressive significance in infants and children. On the other hand the completeness of the primary tumor resection according to oncological standards has been established as the most powerful prognostic parameter superior to tumor marker levels or primary site of the tumor.