Activities of daily living (ADL) may be severely restricted in patients with COPD and assessment requires evaluation of the impact of disability and handicap on daily life. This study is concerned with the development and validation of a standardized 15-item questionnaire to assess routine ADL. Sixty (33 male, 27 female) patients with severe COPD, mean (SD) FEV1 0.91 (0.43) l, median (range) age 70 (50-82) years, completed a 59-item ADL list previously generated by open-ended interview and by literature review. Patients also performed the Shuttle Walk Test (SWT), and completed the St George's Respiratory Questionnaire (SGRQ), the Nottingham Extended Activity of Daily Living Questionnaire (EADL) and the Hospital Anxiety and Depression score (HAD). Criteria for item reduction in the development of The London Chest ADL scale (LCADL) consisted of removal of items where the majority of respondents showed no limitation in the activity (n = 19), where there was no association with perception of global health (n = 9), where an association with age or gender was detected (n = 4), or where items showed poor reliability on test re-test (n = 9). Fifteen items were identified as core activities of daily living. The LCADL was then compared with other measures of health status in these patients. There were good correlations with the SGRQ activity and impact components (p=0.70; P<0.0001) and (p=0.58; P<0.0001), respectively, and EADL (p=0.45; P<0.001), and a moderate correlation with HAD anxiety (p=0.28; P<0.03). There was a significant relationship between the SWT and LCADL (p=0.58; P<0.0001), suggesting a relationship between impaired exercise performance and lower ADL scores. There was evidence of high internal consistency of the questionnaire with Chronbach's alpha of 0.98. These findings suggest that the LCADL scale is a valid tool for the assessment of ADL in patients with severe COPD.