In a cross-sectional epidemiological study in Lieto, Finland, 61 men and 21 women with chronic obstructive pulmonary disease (COPD) were compared with age- and sex-matched controls from the same community to analyze the associations between COPD, cognitive performance, and occurrence of dementia. The cognitive assessment was based on the Mini-Mental State Examination (MMSE), previous clinical documents, and the assessment made by the research nurse after she had interviewed and tested each subject. These three measures revealed no differences between the COPD paients and the age-matched controls, and MMSE subtest scores did not differ significantly between the patients and controls. The findings suggest that the relative contribution of COPD to the occurrence of cognitive impairment and dementia in the elderly may be none or minimal at the community level.