In patients with severe chronic obstructive pulmonary disease (COPD) using long-term oxygen therapy (LTOT), few studies have investigated activities of daily living (ADL). We examined the relationships between ADL, quality of life, mood state and airways obstruction in patients using long-term oxygen therapy (LTOT) and in patients not requiring LTOT. We studied 23 patients (14 males, 9 females; median age 71, range 60-84 yrs) with COPD who received LTOT using oxygen concentrators (LTOT group). We also studied a control group of 19 patients (14 males, 5 females; median age 72, range 62-75 yrs) with COPD but without severe hypoxaemia (non-LTOT group). We found no significant difference between groups in health status using the St George's Respiratory Questionnaire (SGRQ). Median Nottingham Extended Activities of Daily Living (EADL) total scores were: LTOT group 10, non-LTOT 17; (p=0.01). Significant correlations (p<0.001) with Nottingham EADL score were found for Hospital Anxiety and Depression (HAD) score (rho=0.59), SGRQ Total score (rho=0.65) and percentage predicted forced expiratory volume in one second (FEV1) (rho=0.66). In conclusion, in patients with severe chronic obstructive pulmonary disease and broadly similar health status, those using long-term oxygen therapy were less independent in activities of daily living than those not requiring long-term oxygen therapy. Reduced independence in activities of daily living is, however, associated with the extent of airflow limitation, depression and poor health status, and does not, therefore, appear to be simply a result of restriction in movements imposed by the stationary device.