Background: Aggression and crime are connected and highly reported among juveniles in recent times as compared to adults, which ends up in delinquency. It is not just aggression that dominates but the associated impulsiveness also plays a vital role. This study was intended to assess impulsivity and aggression, and their relationship among male delinquent adolescents residing in observation homes. Methods: A quantitative research approach with the nonexperimental descriptive correlation design was adopted. One hundred and seventy-nine male delinquent adolescents residing in 2 observation homes in the state of Bihar, India, were selected by convenience sampling technique. The standardized Buss & Perry Aggression questionnaire, and Barratt Impulsiveness scale were used for collecting the data regarding impulsivity and aggression among male delinquent adolescents. Results: The data were analyzed with descriptive statistics for a description of sample characteristics, and research variables, inferential statistics such as Pearson correlation for correlation, t-test, and ANOVA for the association, and stepwise regression for predictors. Aggression and impulsivity were significantly correlated, there was a significant association of impulsivity with educational status and history of substance use, and the mother’s occupation, educational status, and substance use had predicted the impulsivity. Conclusion: The study concluded that impulsivity and aggression are measurable constructs among male delinquent adolescents, and both were found to be positively correlated. This study had provided initial evidence by filling the gap in the literature to understand the relationship between impulsivity and aggression among juvenile delinquents.