Nutritional depletion commonly occurs in patients with COPD, causing muscle wasting and impaired physiologic function. Two hundred seventeen patients with COPD participated in a placebo-controlled, randomized trial investigating the physiologic effects of nutritional intervention alone (N) for 8 wk or combined with the anabolic steroid nandrolone decanoate (N + A). Nandrolone decanoate or placebo (P) was injected intramuscularly (women, 25 mg; men, 50 mg) in a double-blind fashion on Days 1, 15, 29, and 43. Nutritional intervention consisted of a daily high caloric supplement (420 kcal; 200 ml). Also, all patients participated in an exercise program. In the depleted patients, both treatment regimens induced a similar significant body weight gain (2.6 kg) but different body compositional changes. Particularly in the last 4 wk of treatment, weight gain in the N group was predominantly due to an expansion of fat mass (p < 0.03 versus P and N + A), whereas the relative changes in fat-free mass (FFM) and other measures of muscle mass were more favorable in the N + A group (p < 0.03 versus P). Maximal inspiratory mouth pressure improved within both treatment groups in the first 4 wk of treatment, but after 8 wk only N + A was significantly different from P (p < 0.03). Nutritional supplementation in combination with a short course of anabolic steroids may enhance the gain in FFM and respiratory muscle function in depleted patients with COPD without causing adverse side effects.