Between 1972 and 1980, 58 children with malignant tumors underwent iridium 192 (192Ir) curietherapy at the Institut Gustave Roussy. Data from only 45 of them were reviewed (bilateral retinoblastoma and salvage procedures were excluded). The pathologic diagnosis was rhabdomyosarcoma in 75% of cases, yolk sac tumor in 13% of cases, malignant mesenchymoma in two cases, clear cell carcinoma in two cases, and undifferentiated sarcoma in one case. The two major sites were pelvis-perineum (64.5%) and head and neck (31%). The treatment was essentially based on a combination of chemotherapy, which was adapted to the histologic type of the tumor, and curietherapy. Partial surgery was carried out in certain cases, either before chemotherapy for diagnostic purposes, or after chemotherapy to remove infiltrative residual tumor. External beam radiotherapy was used in a few cases in lymph node irradiation. The radioactive material was 192Ir, using afterloading techniques, either intracavitary or interstitially or both. The tumor dose, calculated by computerized dosimetry, was 60 to 65 Gy delivered over 5 to 7 days in the majority of cases. Two patients were lost to follow-up. Thirty-five patients (78%) are alive with no evidence of disease after a mean follow-up period of 5 years. Eight patients died, one of complications related to chemotherapy and seven of the evolution of their disease. The late-complication rate, studied in 33 patients with a minimum follow-up period of 3 years, is 18% (6/33). Curietherapy seems to be a preferable conservative treatment in children with localized and accessible malignant tumors.