Problematic sleep can be detrimental to the development of important cognitive functions, such as working memory, and may have the potential for negative behavioral consequences, such as risk-taking. In this way, sleep problems may be particularly harmful for youth—whose cognitive abilities are still developing and who are more susceptible to risky behavior. Using data from a large, national, longitudinal study, continuity and change in sleep problems were examined from 2 to 15 years of age and associated with deficits in working memory at age 15 and risk taking behaviors at age 18. Participants (N = 1,364 children; 48.3 % female) were assessed for sleep problems (parent-report), working memory (behavioral task), and risk taking behavior (youth self-report). The sample was predominantly White (80.4 %); additional races represented in the sample included Black/African American (12.9 %), Asian/Pacific Islander (1.6 %), American Indian/Eskimo/Aleut (.4 %), and Other (4.7 %). The findings suggest that sleep problems are likely to cascade across development, with sleep problems demonstrating continuity from infancy to early childhood, early childhood to middle childhood, and middle childhood to adolescence. Although sleep problems in infancy, early childhood, and middle childhood were not directly related to adolescent working memory, sleep problems during adolescence were associated with poorer adolescent working memory. In turn, these deficits in working memory were related to greater risk taking in late adolescence. In summary, the present results suggest that sleep problems in earlier periods are indicative of risk for sleep problems later in development, but that sleep problems in adolescence contribute uniquely to deficits in working memory that, in turn, lead to risky behavior during late adolescence.