The present research aims at testing the psychometric characteristics of the Italian version of Interpersonal Reactivity Index (Davis, 1980) by Bonino, Lo Coco e Tani (1998). The scale is often used to measure empathic reactivity in teenagers and adult. In this study, it was administered to 723 participants in order to test the psychometric structure and reliability. SEM, Rasch model and Cluster Analysis were carried out. They show the presence of three dimensions: Personal Distress and Fantasy are found as in the original version, while Perspective Taking and Empathic Concern, which were distinguished in Davis’ theoretical model, tend to combine and form only one dimension. The emotional and cognitive components of empathy seem to be not differentiable at a measurement level with self-report instruments. Our results are comparable to ones obtained by other authors who administrated the scale in different languages. Finally, the possibility of an IRI short form (18 item) is suggested.