Objectives: The study investigates theoretical debates on the contribution of spiritual, religious, and personal beliefs (SRPB) to quality of life (QoL) in health, by examining contrasting models. Design and method: The WHOQOL-SRPB assesses QoL relating to SRPB where 33 QoL facets are scored in 6 domains, of which SRPB is one. The measure was completed by a heterogeneous sample of 285 sick and well people representing a cross-section of religious, agnostic, and atheist beliefs in UK, and structured for gender (52% female) and age (mean 47 years). Results: No evidence was found to support the model of spiritual QoL as a concept that overarches every other QoL domain. Confirmatory factor analysis showed that SRPB is an integral concept to overall QoL, with a very good fit (comparative fit index = .99). Spiritual QoL made a significant, relatively independent contribution, similar to the other five domains (β = 0.68). Spiritual QoL is most closely associated with the psychological domain, particularly hope and optimism and inner peace; two of the nine SRPB facets. Spiritual QoL, but not most other aspects of QoL, is higher for religious people. Conclusion: The results explain theoretical confusion arising from previous research. Spiritual QoL makes a significant and distinctive contribution to QoL assessment in health and should be assessed routinely in health care populations. © 2010 The British Psychological Society.