The increasing requirement for evaluation of health care, either for purposes of quality assurance or deciding resource distribution issues, has brought into question a number of ideas concerning the aims of the health care enterprise This article suggests that the ultimate aim is to improve the quality of life, and examines the feasibility of adopting this as an evaluation criterion Difficulties concerning the concept and definition of the quality of life are outlined, and a plea made for the adoption of the broadest possible therapeutic aims Social indicators and subjective evaluations are considered in turn as measures of the quality of life, and their inadequacies and strengths exposed Relationships between the measures are discussed, and their uses outlined It is finally suggested that nurses should participate in the formulation of quality of life concepts and evaluations which reflect the values which underpin their own practice