BACKGROUND: We present the results of the TGM-95 study for gonadal sex-cord stromal tumors (SCT). METHODS: Between 1995 and 2005, children (<18 years) with gonadal SCT were prospectively registered. Primary gonadal resection was recommended whenever feasible. Patients with disseminated disease or an incomplete resection received neoadjuvant or adjuvant VIP chemotherapy (etoposide, ifosfamide, cisplatinum). RESULTS: Thirty-eight children with ovarian SCT were registered. Median age was 10.7y. Endocrine symptoms were present in 21 cases. The histological diagnoses were as follows: juvenile (23) and adult (3) granulosa cell tumors, Sertoli-Leydig cell tumors (11), and mixed germ cell SCT (1). An initial oophorectomy ± salpingectomy led to complete resection in 23 patients who did not receive adjuvant treatment; two of them relapsed: one achieved second complete remission whereas the other one died of disease. Fifteen patients had tumor rupture and/or malignant ascites: 11 received chemotherapy and did not relapse, four did not receive chemotherapy and relapsed with a fatal outcome in two cases. With a median follow-up of 5.9y, the 5-y EFS and OS rates were respectively 85% and 94%. Eleven patients had localized testicular tumors (median age 0.83y): juvenile granulosa cell tumors (4), Sertoli or Leydig cell tumors (5) and not otherwise specified SCT (2). Treatment was surgery alone with an inguinal orchiectomy. None have relapsed (median follow-up: 5.4y). CONCLUSIONS: Childhood SCT carry favorable prognosis. In ovarian SCT, surgery should be complete and non-mutilating. Adjuvant chemotherapy efficiently prevents recurrences in cases of tumor rupture. In childhood testicular SCT, the prognosis is excellent with an inguinal orchiectomy, prompting the debate on testis-sparing surgery.