The Perth Emotional Reactivity Scale (PERS) is a 30-item self-report measure of trait levels of emotional reactivity. In this article, we examine the psychometric properties of the PERS subscale and composite scores in an adult community sample (N = 428), and develop an 18-item short form of the measure (PERS–S). The PERS and PERS–S are designed to assess the typical ease of activation, intensity, and duration of one's emotional responses, and do so for positive and negative emotions separately. Our confirmatory factor analyses supported that the PERS and PERS–S both had the same theoretically congruent factor structure, and that all subscale and composite scores displayed high internal consistency reliability. Correlations with scores from established measures of psychopathology and emotion regulation also supported the validity of PERS and PERS–S scores. Our data therefore suggest that the PERS–S subscale and composite scores retain the psychometric strengths of their longer PERS counterparts. We conclude that both forms of the measure have good utility. Clinical and research applications are discussed.