This study investigated the relationship between self-esteem in adolescence and later violent offending and hostility via self- and other-report, examining data from a birth cohort of over 1,000 New Zealand young adults studied to age 25. Lower levels of self-esteem at age 15 were related to greater risks of violent offending and higher levels of hostility at ages 18, 21, and 25. Adjustment for potentially confounding factors reduced the strength of the associations between self-esteem at age 15 and both self- and other-reported violent offending and other-reported hostility at ages 18, 21, and 25 to statistically non-significant levels. The association between self-esteem at age 15 and later self-reported hostility remained statistically significant, but was small in magnitude. A similar pattern of results were obtained using self-esteem at age 10 as the predictor variable in place of the age 15 measure. In addition, a persistent association was found between unstable high self-esteem and self-reported violent offending. The results suggest that self-esteem level plays a limited role in the understanding of violent behavior.