Background: The aim of this study is to investigate the psychometric properties of a new measure of alexithymia, the Psychological Treatment Inventory-Alexithymia Scale (PTI-AS). Method: A group of 778 participants completed the PTI-AS. In order to evaluate aspects of concurrent validity, a part of the sample (n = 116) completed the PTI-AS, the Twenty-Items Toronto Alexithymia Scale (TAS-20) and the Bermond-Vorst Alexithymia Questionnaire (BVAQ). In order to evaluate aspects of discriminant validity a group of patients with a diagnosis of Eating Disorders completed the PTI-AS, the TAS-20 and the Eat-ing Disorders Inventory (EDI-3). Results: Exploratory Factor Analysis (EFA) showed a solid structure with one factor. Results were confirmed by Confirmatory Factor Analysis (CFA), which yielded good fit indices (CFI = .98; TLI = .95; RMSEA = .08; SRMR = .04). The PTI Alexithymia Scale showed a good degree of internal consistency (α = .88). Correlations between the PTI Alexithymia Scale, the TAS-20 (r = .74, p < .001) and the BVAQ (r = .40, p < .001) were statistically significant, supporting the scale's concurrent validity. Conclusion: Thanks to its good psychometric properties the PTI-AS can be consid-ered as a brief and useful measure for assessing alexithymia.