The "ambiance" of a space has an effect on people using the space. In recent years, design for health care environments has begun to include esthetic enhancements in an attempt to reduce stress and anxiety, increase patient satisfaction, and promote health and healing. In this paper, the authors survey the existing research on those elements of the built and natural environment most often asserted by proponents as being inherently healing or promoting health. We postulate a hierarchy of effect of environmental elements ranging from simply nontoxic to safe (both physically and psychologically) to "providing a positive context" to being actively salutogenic. Most relevant research has been concentrated on a limited number of settings and is inadequate to inform the creation of design guidelines for the physical elements of an optimal healing environment. Opportunities exist to make meaningful contributions in this area that are likely to make a significant impact on health outcomes of human beings.