Objective: The goal of the study was to assess the psychometric properties and the factor structure of the Spanish self-report version of the Panic Disorder Severity Scale (PDSS-SR). Method: One hundred and twenty four patients meeting DSM-IV criteria for panic disorder were assessed with the Spanish PDSS-SR, the Anxiety Sensitivity Index-3 (ASI-3), the Sheehan Disability Inventory (SDI) and the Beck Depression Inventory-II (BDI-II). Cronbach's alpha was used to evaluate internal consistency. Pearson correlations were used to evaluate test-retest reliability, convergent and divergent validity. Sensitivity to change data was obtained for 91 patients that had completed a cognitive behavioural therapy. The factor structure was analysed using a confirmatory factor analysis (CFA). Results: The Spanish PDSS-SR showed excellent internal consistency, good test-retest reliability and adequate convergent validity. Regarding divergent validity, the correlation with the BDI-II was larger than expected. The Spanish PDSS-SR was sensitive to change. Our CFA suggested a two-factor model for the scale. Conclusions: The Spanish PDSS-SR has similar psychometric properties as the previous versions of the PDSS-SR and it can become a useful instrument to assess panic symptoms in clinical and research settings in Spanish-speaking countries. © 2014 Elsevier Inc. All rights reserved.