Fourteen patients aged 1 to 15 years with medulloblastoma (six patients), low-grade astrocytoma (four patients), and high-grade astrocytoma (four patients) were treated with carboplatin and etoposide (JET regimen). Six patients had been treated previously, two of them with cisplatin at conventional doses. Carboplatin was administered at 500 mg/m2/day over 5 h on days 1 and 2, in association with pulsed etoposide at 100 mg/m2/day on days 1, 2, and 3. Courses were repeated at 3-week intervals. The disease-specific response rates were as follows: five of six with three complete responses and two partial responses for medulloblastoma; zero of four for low-grade astrocytoma; and two of four with two partial responses for high-grade astrocytoma. Myelosuppression was the main side effect: anemia (hemoglobin less than 8.0 g/dl), thrombocytopenia (less than 25,000/microliter) and leukopenia (less than 1,000 white blood cells/microliters) were noted in 19 of 54, 10 of 54, and 7 of 54 courses, respectively. Gastrointestinal toxicity was very mild, and nephro- and neurotoxicity were not observed. No audiometric abnormalities were demonstrated in seven of seven patients who had not previously received cisplatin, and preexisting audiometric abnormalities were not worsened by the administration of carboplatin in one cisplatin-pretreated patient. The combination of carboplatin and etoposide administered in this study appears to be effective and well tolerated in children with brain tumors. Further studies on a larger number of patients are needed to ascertain its real activity in childhood brain tumors.