Quality of life is a broad concept that incorporates all aspects of an individual's existence. Health-related quality of life is a subset relating only to the health domain of that existence. The utility approach can be used to measure a single cardinal value, usually between 0 and 1, that reflects the health-related quality of life of the individual at a particular point in time. The utility approach is founded in modern utility theory, a normative rational model of decision-making under uncertainty. The measurement techniques that have been used include standard gamble, time trade-off, and rating scales. The techniques are described in the paper and compared in terms of their acceptability to subjects, reliability, precision, validity, and ease of use. It is concluded that the utility approach is beyond the experimental stage, and is now a viable alternative for investigators to use in measuring health-related quality of life.