The aim of this paper was the presentation of modern standards of treatment of adnexal masses in children and adolescents. Main rules of diagnostic procedures should comprise precise imaging procedures and tumour markers assessment. Proper staging is very important before beginning a treatment procedure. Germinal tumours may cause menstrual disturbances, virilisation or precocious puberty. Teratoma maturum is most common of this type of tumours, and is benign disease. Others, like dysgerminoma, teratoma immaturum, endodermal sinus tumour are malignant tumours and should be treated with combined methods. Chemotherapy and surgery are main types of treatment of such tumours. In these cases surgery has to be conservative, because of high chemosensitivity of these neoplasm. One should remember that adjuvant treatment should be administered as soon as possible. Treatment delay may cause fatal consequences. Gonadal neoplasm are second in frequency among ovarian tumours in young girls. Many symptoms may be determined by secretion of oestrogen within this tumour. Granulosa cell tumour is the most common tumour in this group. Only cases diagnosed in stage II and higher or tumour relapses have to be treated with chemotherapy. Proper surgical staging is mandatory to proper evaluation of clinical stage. Surgery should comprise removal of tumour, biopsy from second ovary, multiple biopsy from peritoneum, omentectomy and pelvic and paraaortal biopsy. Such surgery guarantees good surgical staging. Ovarian cancer fortunately is uncommon lesion in ovary in children or in adolescents. Only in stage IA grade 1 conservative surgery treatment can be allowed. Platinum and taxanes compounds are the gold standard in adjuvant treatment of ovarian cancer patients.