Chronic obstructive pulmonary disease (COPD) is an important cause of morbidity and disability. Many studies have investigated factors influencing quality of life (QoL) in middle-aged COPD sufferers, but little attention has been given to elderly COPD. The aim of the present study was to investigate the impact of COPD on QoL and functional status in the elderly. Sixty COPD patients and 58 healthy controls over 65 years old were administered Pulmonary Function Tests, 6 min Walking Test (6MWD) for exercise tolerance, the Barthel Index and Mini Mental State Examination (MMSE) for functional status, the Geriatric Depression Scale (GDS) for mood, and the Saint George Respiratory Questionnaire (SGRQ) for QoL. FEV1 and PaO2 were reduced in COPD patients. Also the distance walked during 6MWD was significantly shorter for patients than controls (282.5 +/- 89.5 vs. 332.9 +/- 95.2 m; P < 0.01). Moreover, COPD patients had significantly worse outcomes for the Barthel Index, GDS and SGRQ. The logistic regression model demonstrated that a decrease in FEV1 is the factor most strictly related to the deterioration of QoL in COPD patients. Mood was also an independent factor influencing QoL. In conclusion, elderly COPD patients show a substantial impairment in QoL depending on the severity of airway obstruction; symptoms related to the disease may be exaggerated by mood deflection.