ABSTRACT: OBJECTIVES:While sleep is critical for good health, it remains a major public health concern because millions of individuals do not obtain a sufficient amount of sleep at night to reap proper health benefits. When examining factors that contribute to deleterious sleep outcomes, few researchers to date have examined the physical and social environments together. STUDY DESIGN:This article is an analytical essay. METHODS:In the present study, 18 empirical articles on environmental factors that promote sleep loss were analyzed and synthesized according to the study type, exposure measures, outcome measures, methodology, and findings. RESULTS:Data from the literature demonstrate that neighborhood airplane, roadway, and rail noise pollution; air pollution from ozone and particulate matter (PM10); and, to some extent, ambient light, interfere with residents' ability to fall asleep, stay asleep, and wake feeling rested. There is also some evidence that neighborhood green space, walkability, safety, built environment, and other social characteristics, such as neighborhood disorder and ability to trust one's neighbors, dramatically impact residents' sleep. CONCLUSIONS:This article provides a critical assessment of the multidimensional relationship between neighborhood physical and social characteristics and sleep, addresses major methodological concerns that limit current empirical knowledge, and suggests steps to shape future research.