The objective of this study was to perform a preliminary item and factor analysis of the Aggression Questionnaire with a sample of Puerto Rican adolescents. The sample consisted of 88 Puerto Rican adolescents between the ages of 14 and 18 years who resided in the metropolitan area of Puerto Rico. An exploratory factor analysis with Varimax rotation revealed a four factor solution that is similar to those found by the author of the questionnaire: physical aggression, verbal aggression, hostility, and anger. The final version of the questionnaire consists of 21 items with factor loadings greater than .30 and a Cronbach’s alpha of .87. Our results indicate that this instrument is reliable and valid to assess different levels of aggression in Puerto Rican adolescents.