This study is a conceptual replication of a widely cited study by Moffitt et al. (2011) which found that attention and behavior problems in childhood (a composite of impulsive hyperactive, inattentive, and impulsive-aggressive behaviors labeled "self-control") predicted adult financial status, health, and criminal activity. Using data from longitudinal cohort studies in the United States (n = 1,168) and the United Kingdom (n = 16,506), we largely reproduced their pattern of findings that attention and behavior problems measured across the course of childhood predicted a range of adult outcomes including educational attainment (βU.S. = -0.22, βU.K. = -0.13) and spending time in jail (ORU.S. = 1.74, ORU.K. = 1.48). We found that associations with outcomes in education, work, and finances diminished in the presence of additional covariates for children's home environment and achievement but associations for other outcomes were more robust. We also found that attention and behavior problems across distinct periods of childhood were associated with adult outcomes. Specific attention and behavior problems showed some differences in predicting outcomes in the U.S. cohort, with attention problems predicting lower educational attainment and hyperactivity/impulsivity predicting ever spending time in jail. Together with the findings from Moffitt et al., our study makes clear that childhood attention and behavior problems are associated with a range of outcomes in adulthood for cohorts born in the 1950s, 1970s, and 1990s across three countries. (PsycInfo Database Record (c) 2023 APA, all rights reserved).