We carried out a prospective randomized controlled trial to investigate the effects of short-term refeeding (16 days) in 10 malnourished inpatients with chronic obstructive pulmonary disease (COPD). Six patients were randomized to receive sufficient nasoenterically administered calories to provide a total caloric intake equal to 1,000 kcal above their usual intake. The other four patients were sham fed, receiving only 100 kcal more. Measurements of nutritional status, respiratory muscle strength and endurance, adductor pollicis function, and pulmonary function were performed initially and at study end. The refed group gained significantly more weight and showed significant increases in maximal expiratory pressure and mean sustained inspiratory pressure. There were no significant changes in the maximal inspiratory pressure or in adductor pollicis function. In malnourished inpatients with COPD, short-term refeeding leads to improvement in respiratory muscle endurance and in some parameters of respiratory muscle strength in the absence of demonstrable changes in peripheral muscle function.