The current study investigated gender differences in the main components of antisocial behavior in an at-risk versus an offender group of adolescents. One-hundred and forty-three adolescents divided into two different risk groups [at risk (n = 54) and offenders (n = 89)] were compared according to gender (111 boys and 32 girls). Externalizing symptoms were assessed with the Delinquent and Aggressive subscales of the Youth Self-report Questionnaire, internalizing problems with the Beck Anxiety Inventory and the Beck Depressive Inventory and personality traits with the Barratt-Impulsiveness Scale as well as the Youth Psychopathic Traits Inventory. Results revealed a consistent interaction pattern, with girls presenting higher levels of externalizing symptoms, more motor impulsivity and a more arrogant and deceitful interpersonal style than boys in the at-risk group. In contrast, in the offenders' group, psychopathic traits were more present in boys than in girls. Regarding internalizing problems, girls showed more depression than boys, independently of the risk group. Among offending youths, girls present equally severe externalizing problems, and problematic personality traits as boys. At-risk girls have the highest rates of difficulties across the tested domains and should therefore be specifically targeted for prevention and intervention.