The RAND-36 is perhaps the most widely used health-related quality of life (HRQoL) survey instrument in the world today. It is comprised of 36 items that assess eight health concepts: physical functioning, role limitations caused by physical health problems, role limitations caused by emotional problems, social functioning, emotional well-being, energy/fatigue, pain, and general health perceptions. Physical and mental health summary scores are also derived from the eight RAND-36 scales. This paper provides example applications of the RAND-36 cross-sectionally and longitudinally, provides information on what a clinically important difference is for the RAND-36 scales, and provides guidance for summarizing the RAND-36 in a single number. The paper also discusses the availability of the RAND-36 in multiple languages and summarizes changes that are incorporated in the latest version of the survey.