The objective of this research was to analyze the psychometric properties of the Aggression Questionnaire (AQ), in its 29, 20 and 12-item versions, in a sample of 898 Chilean students from 14 to 17 years of age. The confirmatory factor analysis identified that the 12-item version was the one showing a more suitable fit to the four-factor model proposed by the authors of the scale. The internal consistency of the four dimensions was acceptable, ranging between .67 and .78. The results also revealed positive and statistically significant correlations between scores of AQ-12-item version and trait and state dimensions of the State-Trait Anger Expression Inventory for Children and Adolescents (STAXI-NA),ranging from .20 (Hostility-State anger) to .57 (AQ total score-Trait anger). These results indicate that the AQ-12-item version is an instrument that shows reliability and convergent validity for evaluating aggressive behaviors in Chilean adolescents.