In dementia there is cognitive impairment, disability in daily life, and sometimes behavioral disturbance. These changes are a burden for the caregivers of patients with dementia. Few studies are available that examine all these aspects and their interrelationships in a single patient group. In our study we selected detailed methods for assessment of all these aspects. Interrelationships were studied in 30 mild to moderately impaired patients with dementia and their caregivers. Although the relations of cognitive deterioration to disability in daily life and of burden experienced by the caregiver to patient's condition were stronger than often reported, it was impossible to deduce the overall severity of dementia from one single aspect. Thus, for effective management of patients and caregivers, for evaluation of individual treatment or of clinical trials, attention should be paid to all the different aspects of patients' condition and caregivers' burden. Outcome measurements will then be more valid.