Carboplatinum, analogue of cisplatin, has been demonstrated to have activity in a spectrum of pediatric tumors. The aim of this study was to determine the efficacy and safety of carboplatinum-based regimens in relapsed or resistant childhood tumors. Carboplatinum was used in two different combinations; 1) combination with etoposide 100 mg/m² iv on days 1-3 plus vincristine 1.5 mg/m² iv on day 1 (CEV); 2) combination with ifosfamide 1500 mg/m²2 iv on days 1-3 with MESNA plus etoposide in the same dose (ICE). Carboplatinum at a dose of 400-500 mg/m² iv was given on day 1 in CEV and on day 3 in ICE. Both regimens were given with a 21-28 days interval. Twelve children (M/F: 1/1, aged 2-17 years) with four different tumor types (NHL, rhabdomyosarcoma, Ewing sarcoma and brain tumor) were analyzed. There were three patients in each group. A total of 80 courses of therapy (32 courses of CEV and 48 courses of ICE) were administered. Response rates after 2 courses of chemotherapy were CR in two, PR in three, SD in five and PD in one patient. Response duration ranged from 2 to 31 months. Up to now, only one patient has been in CR for 23 months. Seven patients died of disease. The remaining four patients are still alive with PD. In 28 courses, G-CSF or GM-CSF was used. Grade III-IV neutropenia and thrombocytopenia were observed in 45% and 35% of the courses, respectively. Febrile neutropenia developed in four courses. In conclusion, carboplatinum-based regimens have significant activity in childhood recurrent or resistant tumors with tolerable toxicity.