Measures of quality of life were obtained on 985 patients with mild hypoxemia and chronic obstructive pulmonary disease (COPD). A subsample of 100 patients were also given extensive neuropsychological and personality tests. Mildly hypoxemic COPD patients showed impairment in quality-of-life activities. They showed less impairment in physical function, compared with previous studies on COPD patients with hypoxemia, but about equal impairment in psychosocial function and dysphoric mood. Nonrelated health changes in life do not seem to account for these findings. Degree of self-reported tension-anxiety was the single greatest predictor of both physical and psychosocial measures of quality of life. Level of exercise completed, forced expiratory volume in 1 s, and neuropsychological status were significantly related to physical limitations, but not psychosocial functioning. The Pao2 was not significantly related to quality-of-life measures in this patient group.