Aim: This paper reports a systematic review to determine the effects of physical environmental stimuli in healthcare settings on the health and well-being of patients. Background: The concept of healing environments suggests that the physical environment of the healthcare setting can encourage the healing process and patients’ feelings of well-being. Understanding the effects of physical environmental stimuli will allow us to design healthcare environments that generate these potential health benefits. Method: A search was conducted using the MedLine, PsychInfo, Embase, CINAHL, Iconda, ScienceDirect, Compendex and the ISI Citation Indexes databases. Studies were included if they concerned interventions involving health effects of environmental stimuli in healthcare settings on patients, and were based on controlled clinical trials published in peer-reviewed journals. Both clinical and psychological outcome measures were included. The search was completed in 2005. Findings: Of the over 500 potentially relevant studies identified, only 30 met all criteria and were included in this review. Predominantly positive effects were found for sunlight, windows, odour and seating arrangements. Inconsistent effects were found for sound, nature, spatial layout, television and multiple stimuli interventions. In general, both the size and direction of effects seem highly dependent on characteristics of patient populations and healthcare settings. Conclusions: Studies that manipulate several environmental stimuli simultaneously clearly support the general notion that the physical healthcare environment affects the well-being of patients. However, when scrutinizing the effects of specific environmental stimuli, conclusive evidence is still very limited and difficult to generalize. The field thus appears to be in urgent need of well-conducted, controlled clinical trials. At present, and on the basis of the available research, it would be premature to formulate evidence-based guidelines for designing healthcare environments.