Nutritional insult after bone marrow transplantation (BMT) is complex and its nutritional management challenging. Enteral nutrition is cheaper and easier to provide than parenteral nutrition, but its tolerance and effectiveness in reversing nutritional depletion after BMT is poorly defined. Nutritional status, wellbeing, and nutritional biochemistry were prospectively assessed in 21 children (mean age 7.5 years; 14 boys) who received nasogastric feeding after BMT (mean duration 17 days) and in eight children (mean age 8 years, four boys) who refused enteral nutrition and who received dietetic advice only. Enteral nutrition was stopped prematurely in eight patients. Greater changes in weight and mid upper arm circumference were observed in the enteral nutrition group, while positive correlations were found between the duration of feeds and increase in weight and in mid upper arm circumference. Vomiting and diarrhoea had a similar incidence in the two groups, while fever and positive blood cultures occurred more frequently in the dietetic advice group. Diarrhoea occurring during enteral nutrition was not associated with fat malabsorption, while carbohydrate malabsorption was associated with rotavirus infection only. Enteral feeding did not, however, affect bone marrow recovery, hospital stay, general wellbeing, or serum albumin concentrations. Hypomagnesaemia, hypophosphataemia, zinc and selenium deficiency were common in both groups. In conclusion, enteral nutrition, when tolerated, is effective in limiting nutritional insult after BMT. With existing regimens nutritional biochemistry should be closely monitored in order to provide supplements when required.