The aim of this study was to explore the effect and ascertain the ideal dose of recombinant human growth hormone (rhGH) for the treatment of geriatric thoracic and abdominal postoperative patients with acute respiratory failure. Forty-five geriatric postoperative patients with acute respiratory failure were randomly divided into three groups (A, B and C). Patients in rhGH group A were given 4 IU rhGH by intramuscular injection twice a day continuously for 10 days. Patients in rhGH group B were given 4 IU rhGH by intramuscular injection once a day continuously for 10 days. Patients in control group C were admitted to the intensive care unit (ICU), but were not given rhGH. Other treatments were the same in the three groups. Comparisons were made among the groups regarding time of mechanical ventilation, average time in the ICU, success rate of one time pull out windpipe conduit, incidence rate of ventilatorassociated pneumonia and case fatality rate, blood glucose content, and dosage of insulin per day from the beginning of the treatment until the 10th day. Compared with the control group, the parameters of recovery of respiratory function and fatality in the ICU of treatment groups A and B all showed statistically significant difference (P < 0.05). Although the blood glucose in group C showed no difference before and after treatment (P > 0.05), the blood glucose of rhGH group A became mildly elevated after treatment (P > 0.05) whereas that of group B showed the opposite effect (P < 0.05). Accordingly, the required dosage of insulin per day was much more than that before treatment (P < 0.05) in the controllable range. A daily rhGH dose of 4 IU for 10 days is safe for geriatric thoracic and abdominal postoperative patients with acute respiratory failure in the ICU. However, enhanced monitoring of blood glucose and intensive insulin therapy (IIT) should be conducted to prevent glycometabolic disturbance.