We studied the effect of total parenteral nutrition on recovery from myelosuppression in patients receiving intensive chemotherapy. Twenty-seven patients (ages 11 to 33 years) with locally recurrent or metastatic Ewing's sarcoma, rhabdomyosarcoma, or osteosarcoma were randomly selected to receive either conventional oral nutrition or total parenteral nutrition concurrently with intensive chemotherapy. The control group (15 patients) received significantly fewer calories (range 380 to 880/m2 per day, median 685 versus range 1,020 to 2,100 median 1,650) and less nitrogen (0-3.7 g/m2 per day, median 1.5 versus range 5.3 to 12.4, median 8.9) than the group receiving total parenteral nutrition (12 patients). Assessment of recovery from myelosuppression was based on the length of time the absolute granulocyte count was below 500/mm3, the length of time the platelet count was below 40,000/mm3, the number of days the platelet count was below 20,000/mm3, and the number of blood transfusions required. There was no statistical difference in any of the parameters evaluated between the group that received total parenteral nutrition and the control group (p less than 0.05); granulocyte and platelet recovery and the difference in transfusion requirements favored the control group with marginal statistical significance (p = 0.05). The frequency of clinical infections was similar in the patients receiving total parenteral nutrition (five of 12) and in those receiving conventional oral nutrition (five of 15). Thus, although total parenteral nutrition could be safely administered in this severely myelosuppressed population, no benefit could be defined in recovery from bone marrow suppression or frequency of clinical infections.