Utility is a simple expression of health-related quality of life in individuals with different states of health. A number of studies on utility measurements were conducted and published in the past. We retrieved 164 English-language articles which appeared in 1966 through 1999 for a systematic review.The number of reports has been increasing at an accelerating pace, especially during the past decade. The most widely used method of utility measurement was time trade-off, TTO (40%), followed by rating scale, RS (31%) and standard gamble, SG (29%).The utility of chronic health status was more frequently reported as compared with acute health status (907 vs 86). Accordingly, frequently explored clinical categories were cardiology, neurology, nephrology, and gastroenterology. Specifically, coronary heart disease (52 utilities), physical disability due to neurological diseases (45 utilities), chronic renal failure (74 utilities), and colorectal cancer (29 utilities) were subject to utility measurement. Mental or social dysfunctioning accounted for only a small proportion (48 utilities). There is a strong tendency for RS to yield the lowest and SG to yield the highest values.We compiled an extensive list of the results of studies on utility as a reference for health care professionals in this field. J Epidemioi, 2002 ; 12 :160-178