The Adapted Self-Report Delinquency Scale (ASDS) was administered to 328 adolescents (174 males and 154 females) from eight high schools in Perth, Western Australia. The ages of the sample ranged from 13 to 17 years. Males reported a greater percentage level of involvement than females in 36 of 40 individual delinquent behaviours comprising the ASDS. A between-subjects multivariate analysis of variance using a Bonferroni adjusted alpha revealed a significant multivariate main effect of gender, "F"(6, 318) = 3.98, "p"?less than?0.001, partial "eta[superscript 2]"?=?0.08. No significant main effect of age was evident. Univariate "F"-tests revealed that males scored significantly higher than females on only one of seven delinquent factors (physical aggression). These data are discussed in light of established evidence showing male predominance in delinquency, recent reports suggesting a male-female gender gap, and theories that have attempted to explain this disparity in offending among males and females. (Contains 2 tables.)