Despite reservations made on its use as a means for evaluating interventions, various findings in the recent literature point to patients' and relatives' satisfaction with psychiatric services as a particularly salient and appropriate measure of outcome and quality. Even though substantial improvements have occurred in the last decade, research in the field suffers various methodological limitations regarding the study design, the instruments' construction and the lack of attention to their psychometric properties. In the last few years the need for research that develops and refines measures of client satisfaction and establishes their psychometric properties has been considered a priority in service evaluation by a growing number of authors. In spite of this, in the mental health field very few validated instruments for the measurement of satisfaction are currently available. The aims of the present paper were: (1) to update work done in the field of satisfaction with mental health services in the last decade; (2) to describe the main instruments currently available to measure patients' and relatives' satisfaction with mental health services; (3) to provide guidelines for the future development of instruments and their use in mental health settings. The author concludes by emphasizing that, in order to make further progress, considerable effort is needed in developing and spreading the use of validated instruments and discouraging the use of ad hoc measures. Comparability between studies should be pursued more vigorously in order allow both the refinement of existing instruments and a better understanding of the theoretical and substantive meaning of satisfaction with psychiatric services.