Abstract The reliability and validity of the Toronto Structured Interview for Alexithymia (TSIA) have been demonstrated in previous studies with English-speaking community and psychiatric samples and a German-speaking psychiatric sample. The aim of this study was to evaluate the psychometric properties of the TSIA in a mixed clinical and nonclinical sample from Italy. The original English version of the TSIA was translated into Italian and administered, along with the 20-item Toronto Alexithymia Scale (TAS-20), to 80 healthy subjects, 69 medical outpatients, and 62 psychiatric outpatients. Eighty-one videotaped interviews were used for assessing the interrater reliability. Confirmatory factor analysis supported the hierarchical, four-factor structure of the TSIA obtained in previous studies, with four lower-order factors nested within two higher-order latent factors. The TSIA also demonstrated internal and interrater reliability, and concurrent validity with the TAS-20. The results support the use of the TSIA to assess alexithymia especially when a multimethod approach to measurement is possible.