AIM: To investigate the effectiveness and safety of recombinant human growth hormone (rhGH) in postoperative patients.METHODS: A total of 48 consecutive patients undergoing abdominal operations were randomized to receive either subcutaneous rhGH (0.15 IU/kg) or placebo (menstruum) injections daily for 7 d after surgery. The two groups had similar nutritional intake. Blood samples for serum fibronectin, albumin, prealbumin, transferrin and the total lymphocyte count, as well as glucose levels were collected to study the rhGH effect. Basal laboratory evaluation, and nutritional status were estimated on d 1before as baseline and d 3 and 10 after operation using standard laboratory techniques. Nitrogen balance was measured from d 3 to 9 after operation.RESULTS: The cumulative nitrogen balance was significantly improved in rhGH group compared with the placebo group (11.37±16.82 vs -9.11±17.52, P = 0.0003).Serum fibronectin was also significantly higher in the rhGH group than in the placebo group (104.77±19.94vs 93.03±16.03, P＜0.05), whereas changes in serum albumin, prealbumin, transferrin and total lymphocyte counts were not statistically significant. Mean blood glucose levels were significantly higher in the rhGH group from d 3 to 6 after operation.CONCLUSION: If blood glucose can be controlled, lowdose growth hormone together with hypocaloric nutrition is effective on improving positive nitrogen balance and protein conservation and safe is in postoperative patients.