As advances in medical science have extended the limit of viability downward to 23 or 24 weeks gestation, interest has turned from long-term health outcomes to quality of life for survivors. During the last decade, the first studies of the health-related quality of life (HRQOL) of children and young adults who were born extremely preterm were published. Taken from the fields of anthropology, economics, sociology, and psychology, the foundation of HRQOL is formed by theories of functionalism, positive well-being, and utility. HRQOL can be defined as the physical, psychological, and social domains of health, which can be influenced by an individual's experiences and perception. HRQOL instruments are generally composed of multiple domains and measure physical functioning, mental health, and social role functioning in some form. Utilities, or preferences for health outcomes under conditions of uncertainty, are also used. Studies of HRQOL to-date indicate that preterm children have, on average, poorer health than their normal birthweight peers, but the majority do not perceive their quality of life as significantly different than others of their own age. Measures of HRQOL should not replace the traditional measures of morbidity, but should become part of the standard battery of tools used to assess a preterm child's health and well-being. Ultimately, studies of the HRQOL of preterm children should identify aspects of life, physical, psychological, or social, that could be improved with intervention.