Background: Research on children's emotional behaviour has been hampered by the lack of psychometric assessment scales. The present study reports on the construction and validation of a new self-report instrument to measure the emotional response styles of adolescents. Method: Exploratory and confirmatory factor analyses were carried out on the responses of three samples of adolescents aged between 11 and 14 years (total = 609) to an item pool derived from a scenario study. In addition to assessing reliability, the final form of the questionnaire was concurrently validated using a variety of related psychometric instruments as well as teacher ratings of pupils' behaviour. Results: The factor analyses of the item pool yielded three independent factors labelled social anxiety, malevolent aggression, and social self-esteem. These categories correspond closely to the three dimensions that have emerged consistently from studies of children's temperament, labelled inhibited, undercontrolled and well-adjusted. The three factors comprising the final Emotional Behaviour Scale (EBS) all demonstrated satisfactory internal (coefficient alpha) and re-test reliability. Concurrent validation showed that the three factors were related in predictable ways to other related constructs, and comparisons with teacher ratings of pupils confirmed the relationship between the EBS subscales and children's actual social and emotional behaviour. Conclusion: The new scale offers a valid and reliable instrument for assessing adolescent emotional behaviour, and current work is aimed at extending the research to the assessment of young offenders.