With reference to the multidimensional four-factor model, the two Asian samples in the study had a better fit compared with Bryant and Smith's (2001) reported goodness-of-fit statistics for the three datasets from the United States, Great Britain, and Canada. Collectively, the findings show that the multidimensional model and its hierarchical counterpart are acceptable measurement models for the 12-item AQ measure, as evidenced by appropriate goodness-of-fit statistics for Western as well as Asian samples. The study also demonstrated that in addition to undergraduates and older adolescents, the multidimensional AQ structure was valid for a much younger sample (mean ages for the two Asian samples were 13.67 and 12.23, respectively). Consistent with other AQ validation studies, the current findings show males to be more physically aggressive than females in both samples, and males were more verbally aggressive than females in one of the samples. No other gender differences were found. Both genders have consistently shown similarity on anger. The first sample consisted of 331 adolescents (171 boys and 160 girls) from 3 schools in Singapore. Their ages ranged from 13 to 17. The second sample consisted of 370 adolescents (176 boys and 194 girls) from 2 schools in Singapore that were not part of the other sample. The 12-item short version of the AQ was used. The four subscales were physical aggression, verbal aggression, anger, and hostility. 3 tables and 52 references