A 16-year-old boy with type I GSD has been treated with parenteral nutrition, continuous intragastric feeding, and portacaval shunt. The effects of these treatment methods have been compared with reference to changes in blood chemical values, platelet function, and clinical status. Each of the treatment procedures was effective in improving clinical status and in reducing the levels of blood lipids. Portacaval shunt was less effective than the other treatment methods in reducing either the uric acid levels or the tendency to develop hypoglycemia, or in correcting the platelet dysfunction. Despite these observations the patient has grown 4 inches in 5 months since introduction of the shunt. The implications of these findings are discussed.