IntroductionDespite previous research delving into the trajectories of delinquency during adolescence and their links to parental warmth, there remains a notable gap in understanding cultural differences in these trajectories and associated factors. This study sought to address this gap by examining and comparing the levels and trajectories of delinquency, along with their association with parental warmth, between the United States and South Korea.MethodThe study included American adolescents (N = 5,665) from the National Longitudinal Study of Adolescent to Adult Health (Add Health) at Wave I (1995), II (1996), and III (2001) and Korean adolescents (N = 3,449) selected from the Korean Youth Panel Survey at Wave I (2003), II (2004), and VI (2008). The participants, including both adolescent boys and girls at the age of 14/15 at Wave I, completed surveys at each wave.ResultsResults from latent growth curves showed that delinquency levels peaked in middle adolescence and declined thereafter in both countries. The initial level of delinquency was higher for American adolescents than for Korean adolescents, however, the slope of delinquency declined faster for American adolescents than for Korean adolescents. Further, the protective effect of parental warmth on delinquency was stronger for Korean adolescents than for American adolescents.ConclusionThe cultural differences in the levels and trajectories of delinquency, along with the different strengths of the protective effect of parental warmth, highlight the importance of considering cultural contexts in understanding delinquency trajectories and the protective role of parental warmth against delinquency.