Six patients with bilateral Wilms' tumor presenting between 1978 and 1999, were analysed retrospectively. These cases occurred among 108 patients of Wilms' tumor giving an incidence of 5.5%. The mean age of presentation was 3 years (range 9 months-6 years) and cases received treatment according to 'National Wilms' Tumor Study Group (NWTS)' 2,3 and 4 protocols. Two cases received preoperative chemotherapy and two received postoperative radiotherapy. The surgical modalities were: biopsy (1), bilateral partial nephrectomy (3), unilateral nephrectomy and contralateral partial nephrectomy (1) and tumor enucleation (1). The vena caval thrombus extending into the right atrium was removed under open heart surgery conditions. In the postoperative period one patient died of renal insufficiency and another case died of septicemia in the 5th postoperative month. Among the 3 cases surviving, two are free of problems over 5 years. Preoperative chemotherapy is the key treatment modality in providing kidney preserving surgery especially in bilateral involvement and disseminated tumors. The surgical and oncological treatment results for bilateral Wilms' tumor have improved over the years with the application of current modalities.