BACKGROUND: As terminal disease progresses, health deteriorates and the end of life approaches, people may ask "Why this illness? Why me? Why now?" Such questions may invoke, rekindle or intensify spiritual or religious concerns. Although the processes by which these associations occur are poorly understood, there is some research evidence for associations that are mainly positive between spiritual and religious awareness and wellness, such as emotional health. OBJECTIVES: This review aimed to describe spiritual and religious interventions for adults in the terminal phase of a disease and to evaluate their effectiveness on well-being. SEARCH METHODS: We searched 14 databases to November 2011, including the Cochrane Central Register of Controlled Trials and MEDLINE. SELECTION CRITERIA: We included randomised controlled trials (RCTS) if they involved adults in the terminal phase of a disease and if they evaluated outcomes for an intervention that had a spiritual or religious component. Primary outcomes were well-being, coping with the disease and quality of life. DATA COLLECTION AND ANALYSIS: In accordance with the inclusion criteria, two review authors independently screened citations. One review author extracted data which was then checked by another review author. We considered meta-analysis for studies with comparable characteristics. MAIN RESULTS: Five RCTs (1130 participants) were included. Two studies evaluated meditation, the others evaluated multi-disciplinary palliative care interventions that involved a chaplain or spiritual counsellor as a member of the intervention team. The studies evaluating meditation found no overall significant difference between those receiving meditation or usual care on quality of life or well-being. However, when meditation was combined with massage in the medium term it buffered against a reduction in quality of life. In the palliative care intervention studies there was no significant difference in quality of life or well-being between the trial arms. Coping with the disease was not evaluated in the studies. The quality of the studies was limited by under-reporting of design features. AUTHORS' CONCLUSIONS: We found inconclusive evidence that interventions with spiritual or religious components for adults in the terminal phase of a disease may or may not enhance well-being. Such interventions are under-evaluated. All five studies identified were undertaken in the same country, and in the multi-disciplinary palliative care interventions it is unclear if all participants received support from a chaplain or a spiritual counsellor. Moreover, it is unclear in all the studies whether the participants in the comparative groups received spiritual or religious support, or both, as part of routine care or from elsewhere. The paucity of quality research indicates a need for more rigorous studies.