This chapter discusses the research pertaining to six different types of risks, and addresses these risks in the context of Bronfenbrenner's Ecological Systems theory. It examines the following environmental risks directly related to the child: demographic characteristics; parenting practices, attitudes, and beliefs; and maternal mental health. The risks also include home environment, as well as aspects of the child's environment that connect the child to the broader community, such as neighborhood; and a broader exposure to risk through environmental toxins. A cumulative risk model of development posits that adverse developmental outcomes can be better predicted by combinations of risk factors than by single risk factors. The chapter considers three promising avenues for future risk research: the use of statistical methods such as recursive partitioning to examine nonlinear effects, resilience or the ability of children to thrive despite the presence of risks, and the role of gene-environment interaction in understanding risk.