This paper describes three studies. The first is concerned with the relationship between the Aggression Questionnaire (AQ) and a peer-report version of the AQ (AQ-P). The results (from a sample of 77 men aged 19 to 55 years) showed agreement between the two versions, thus providing evidence for the congruent validity of the AQ-P, and good internal consistency was shown for the subscales of the AQ and AQ-P. The second study involved the development, piloting, and validation of a vignettebased assessment of aggressive behavior, the Aggressive Provocation Questionnaire. The third concerned the use of the finalised Aggressive Provocation Questionnaire in a sample of 130 men (aged 17 to 54 years). The results show that prior self-reported aggression (measured by the AQ) predicted responses to provoking scenarios. Younger men (< 28 years) showed an association between physical aggression and the aggressive action scale (of the Aggressive Provocation Questionnaire) in response to provoking scenarios. Older men (> 28 years) showed an association between physical aggression and the assertive action scale. The findings are discussed in relation to aggression measurement and changes in aggression with age. Aggr. Behav. 27:79-101, 2001.