Reports or research investigations studying children in nature are rapidly expanding and increasingly diverse. This document reports a review of a particular part of this field-studies of constraints to recreation and participation in environmental and outdoor recreation programs. The findings result from a review of more than 125 journal articles, books, and reports that were published between 1980 and 2009. This report discusses how the current information concerning constraints to participation can be understood in terms of four concentrations or foci of work generated in this particular field of study. These foci, which are all well established in the literature, are (1) intrapersonal, interpersonal, and structural constraints, (2) significant life experiences, (3) environmental attitudes, values and beliefs, and (4) environmental behaviors. The recent research associated with each of these research areas is discussed in successive sections of the review. Overall, this review found that the research on constraints that inhibit children's connection to nature is less diverse in terms of methodological and theoretical approaches than is the research into the broader outdoor recreation research field within which it is situated. This review focused on the issue of connecting children with nature, but examples from studies using adults to understand childhood experiences and recreation preferences were used because there are relatively few peer-reviewed articles showing the theoretical or empirical connection of children and nature. In some cases, broader empirical studies were used to connect with larger themes (that is, environmental attitudes, beliefs, and values).