The aim of this study was to examine the impact of pain on quality of life and its components in a representative sample of 320 well people, and patients selected from all major categories of illness. Quality of life was assessed using a new, multidimensional, multilingual, generic profile designed for cross-cultural use in health care, i.e. the WHOQOL. Within the WHOQOL, pain and discomfort is one of 29 areas or facets of quality of life, grouped into six domains. It was found that pain and discomfort made a significant impact on perceptions of general quality of life related to health. Furthermore, the presence of pain affected perceptions of five of the six domains of quality of life; the domain of spirituality, religion and personal beliefs being the exception. When quality of life is assessed, negative feelings are most closely associated with reports of pain and discomfort than any other facet. But quality of life surrounding pain and discomfort is more fully explained by the inclusion of six additional facets; the availability of social care, mobility, activities of daily living, positive mood and to a lesser extent, sleep and dependence on medication. Together, these seven facets represent criteria against which the success of pain treatments may be evaluated. As predicted, those who were pain-free had significantly better quality of life than those in pain. A longer duration of pain is associated with increasingly poorer quality of life. Intense affective pain is particularly detrimental to a good quality of life. The psychometric properties of the pain and discomfort facet of the WHOQOL and WHOQOL-100 were assessed. Internal consistency (reliability), discriminant and criterion/concurrent validity were found to be good to excellent, justifying the use of this instrument with a range of chronic and acute pain patients.