Youth violence is a public health threat in the United States. Inadequate sleep is identified as a risk factor, however, the majority of previous studies were cross-sectional and focused only on adolescents. This study aimed to investigate the association between average hours of sleep during adolescence and violent behavior among youths. Individuals who participated in both Waves II (1996) and III (2000-2001) of National Longitudinal Study of Adolescent and Adult Health (n=3,557) were included. A composite variable on violent behavior was created using three different questions on fighting or using a weapon. Age, gender, ethnicity, violent behavior during adolescence, depressive symptoms, impulsivity, and current sleep hours were considered as covariates. Negative binomial regressions were conducted using SAS 9.4. The mean age of the participants was 15.85 years (SD=1.62) and 21.29 years (SD=1.60) in waves II and III, respectively. The majority of the participants were female (54.15%) and non-Hispanics (88.93%). Average hours of sleep during adolescence was not significantly associated with violent behavior during young adulthood (p=0.75). In the final model, gender (beta=1.65, p<0.001), age (beta=-0.1267, p<0.001), history of violent behavior (wave II) (beta=0.3158, p<0.0001), current average hours of sleep (wave III) (beta=-0.073, p=0.044), depressive symptoms (beta=0.0834, p <0.0001), and impulsivity (beta=0.1379, p<0.0001) were significantly associated with violent behavior in early adulthood. Reduced number of sleep hours during early adulthood, unlike during adolescence, increased the likelihood of getting involved in violent activities during early adulthood. This information is useful to promote healthy behavior among individuals in all phases of their life.