The aim of this study was to evaluate the psychometric properties of the Dutch version of the Toronto Structured Interview for Alexithymia (TSIA) in a clinical sample. The TSIA and the 20-item Toronto Alexithymia Scale (TAS-20) were administered to 85 psychiatric inpatients and to 76 medical outpatients with the symptom of tinnitus. Both internal and inter-rater reliability were acceptable. Confirmatory factor analyses supported the hierarchical, 4-factor structure with 4 lower-order factors nested within 2 higher-order latent factors, previously obtained with English, German, and Italian versions. Concurrent validity was supported by significant correlations between the TSIA and the TAS-20 total scores although there were some differences between the psychiatric subsample and the medical subsample. While further studies are needed to assess the convergent and discriminant validity of the TSIA, the results support its use as a measure of alexithymia.