The introduction of cholinesterase inhibitors to improve the cognitive function and activities of daily living in patients with Alzheimer disease, raises the question whether these drugs also have the potential to improve the quality of life of these patients. In this article a model is presented to measure quality of life in patients with dementia, in which psychological well-being is chosen as the central measure. The presented model might be the starting point to develop instruments to measure quality of life in dementia. After a short introduction concerning the developments in quality of life research, the two most important characteristics of the concept--multidimensionality and subjectivity--are discussed against the background of the relevant literature on dementia. The dementia-specific dimensions--individual characteristics, psychological, social and physical dimension, and environment--and domains are presented, and put in a hierarchical model.