Malignant ovarian tumours in childhood are rare. Germinal cell tumours are the most common tumours and are extremely malignant, with the exception of dysgerminomas. The possibilities of therapy have improved considerably in the last 3 to 4 years, thanks to combined chemo- and radiotherapy following surgical resection of the tumour. Exact staging at the beginning of therapy is very important. A second operation, primary or as a second look procedure, is recommended after emergency operations. Therapy should be carried out in pediatric oncology centres. Because of the invasive measures, medical and psychological care are necessary after the conclusion of therapy. The rarity of these tumours should prevail upon us to organize national and international therapeutic studies.