The Perth Emotional Reactivity Scale (PERS) is a newly developed 30-item self-report measure of emotional reactivity (affective style). The PERS measures the typical ease of activation, intensity, and duration of one’s emotional responses, and importantly does so for negative and positive emotions separately. We examined the psychometric properties of the PERS in an adult community sample (N = 183). Confirmatory and exploratory factor analyses supported the capacity of the PERS to measure separate negative and positive reactivity factors, and to distinguish between the activation, intensity, and duration aspects of reactivity. All items of the PERS had strong loadings on their intended factor. Concurrent validity was supported via congruent correlations with other emotion measures, and internal reliability was good to excellent for all PERS scales and subscales. Overall, the PERS appears to have good psychometric properties, and thus has promising utility for research and clinical settings.