This article presents a review of major empirical research on environmental justice. Forty-two empirical research studies spanning three decades were evaluated and categorized on the basis of how well they meet reasonable scientific standards. Twelve of those studies are described and critiqued in detail, and an overview of trends in the literature is presented. The author concludes that the empirical foundations of environmental justice are so underdeveloped that little can be said with scientific authority regarding the existence of geographical patterns of disproportionate distributions and their health effects on minority, low-income, and other disadvantaged communities. If environmental managers and policy-makers do not recognize the high levels of empirical uncertainty surrounding the issue, they are apt to attribute an empirically unwarranted level of concreteness to the empirical research findings, thus leading to poorly conceptualized and therefore potentially harmful policy and management decisions.