In the context of growing attention for 'healing environments' and 'evidence based design' an increasing number of hospitals have decided to provide single-bedded rooms. However it remains unclear to what extent these policy decisions are based on scientific evidence. The aim of this study is to review the literature on benefits of single patient rooms for patients. The following outcome measures were used: privacy and dignity, patient satisfaction with care, noise and quality of sleep, hospital infection rates, recovery rates, and patient safety issues. We selected 25 studies for review. Randomized controlled trials on this subject were scarce, but other empirical studies have been found. We found that single rooms have a moderate effect on patient satisfaction with care, noise and quality of sleep, and the experience of privacy and dignity. Conflicting results have been found on hospital infection rates. Some studies did not show significant differences, while others concluded that single rooms decrease the risk of hospital infections. Evidence on recovery rates and patient safety was lacking. Too few sound studies were found to evaluate the effects of single patient rooms thoroughly. Future research should build the body of knowledge on single-bedded rooms in order to explore their impact on well-being and healing on both patients and staff. Also consequences of single rooms to management of care should be explored. Research should support policy making by exploring, indicating and initiating improvements in patient housing and quality of care.