In a cost-effectiveness analysis, the costs of 55 demented patients in day care (DC) and 45 patients on a waiting list were related to the effects on indices measuring quality of life. Based on one year's study, the costs per patient per day, was USD 55 for the DC-group and USD 63 for the controls (p > 0.05). Both groups deteriorated in the indices during the study year. The trend was that DC was both cheaper and better in the indices, and some of the underlying variables for the used indices also showed significantly better results in favour of DC. However, since the changes between the groups were not significant regarding the basic question at issue, it cannot be stated that DC is more cost-effective than a care organisation without DC. Different interpretations of the results are presented.