OBJECTIVE--To describe and analyse the problems in self-maintaining activities among chronic obstructive pulmonary disease (COPD) patients aged 64 years and over. DESIGN--A case-control study. SETTING--Health Centre in Lieto, Finland, 1990-91. SUBJECTS--61 men and 21 women with COPD and 183 male and 63 female sex- and age-matched controls. The COPD group included 8 men and 11 women who also had asthma. MAIN OUTCOME MEASURES--Numbers of subjects with difficulties or dependence in self-maintaining activities. RESULTS--The number of subjects with difficulty or dependence in the activities of daily living (ADL) was similar among the patients and the controls, but some differences between the two groups were seen on items of mobility and instrumental activities of daily living (IADL). The COPD patients had more difficulties or showed dependence in moving outdoors or walking at least 400 m. In addition, the male COPD patients reported more difficulty or dependence in doing heavy housework and the female patients in even doing light housework than the controls. CONCLUSION--The study indicated that the female COPD patients in particular have a great need for assistance in self-maintaining functions. This information is valuable for local primary health care planning.