The aim of this study was to assess the effect of a low-dose testosterone on body composition and pulmonary function, as well as on quality of life, sexuality, and psychological symptoms in patients with chronic obstructive pulmonary disease (COPD). Twenty-nine men with moderate to severe COPD were allocated to receive either 250 mg of testosterone or placebo intra-muscularly, every fourth week, during the 26 weeks study period. Fat-free mass increased in the treatment group (P<0.05), and a significant difference between the treatment and the control group was seen after 26 weeks (P<0.05). Fat mass decreased in the treatment group (P<0.05), and there was a significant difference between the treatment and the control group after 12 weeks (P<0.01). A significantly better erectile function was reported in the treatment group at the final visit (P<0.05), and the overall sexual quality of life was significantly better in the treatment group after 12 weeks (P<0.05). No improvement in pulmonary function was found. In conclusion, administration of a low-dose testosterone to men with COPD for 26 weeks was associated with improvement of body composition, better erectile function and sexual quality of life. Furthermore, there were no clinical or biochemical side effects.