Existing measures of criminal attitudes and associates have rarely been tested with samples of female offenders or incorporated gender-informed variables. The study examined the reliability and validity of the Measure of Criminal Attitudes and Associates with 312 adolescent offenders (102 females, 210 males). Additionally, the study examined whether the predictive validity of the Criminal Friend Index could be enhanced by incorporating two gender-informed variables. Results show that the MCAA is reliable for males (α = .65 to .91) and females (α = .62 to .89). and that the CFI component of the MCAA predicts reconvictions for males (AUC = .64) but not females (AUC = .53), but the total attitude score predicted for both genders (males, AUC = .61; females, AUC = .70). However, incorporating gender-informed variables into the CFI did not improve predictive accuracy. The need to develop gender-informed measures from the ground-up for female offenders is discussed.