Ewing's sarcoma (ES) is rarely diagnosed in the pre-school age; these few cases however present a number of difficult diagnostic and therapeutic problems. The Authors describe a series of six such cases aged less than 4 years diagnosed in the period 1974-1987. Standard treatment was modified with the purpose to reduce acute toxicity and late sequelae. These modifications are described in details. Four/6 patients are presently alive disease-free from 29 to 87 months from diagnosis (median, 34 months). Two patients died from acute toxicity. The Authors suggest that young children with ES may be treated successfully with proper adjustments of current protocols. Increased aggressiveness of chemotherapy regimens may compensate for reduced radiotherapy; however, the high susceptibility to infection of youngsters has to be taken into account and makes mandatory a careful monitoring during phases of profound myelodepression.