In 52 children with cancer, the effect of nutritional status on infection rate was studied. Thirty-two children had solid tumors and 20 had leukemia. Their treatment courses were arbitrarily divided into 3-month periods. Where treatment lasted for 9 months or more, the initial Nutritional Status score was correlated with infection rate during the subsequent 3-month period. Among the leukemic patients, a statistically significant inverse correlation (P < 0.05) was found between nutritional status and ensuing infection rate. No such correlation was found in children with solid tumors. Based on these findings, we recommend nutritional support to children with leukemia during chemotherapy to attempt to reduce the infection rate.