Objective Research suggests that emotions and emotion regulation processes can influence both the sensory (e.g., intensity) and the affective (unpleasantness) components of pain. The purpose of this study was to investigate the factor structure and validity of the Difficulties in Emotion Regulation Scale (DERS; Gratz and Roemer, 2004) in medical sample with persistent pain. Method Data were collected from 207 chronic pain patients (82.6% female; mean age = 51.96). We applied confirmatory factor analysis (CFA) to test measurement model of emotion dysregulation and CFA with covariates to test construct and convergent validity of the DERS. Results The original factor structure of the DERS was not supported in our medical sample. However, after some modifications the DERS yielded good fit. Validity of the DERS was confirmed. All the subscales had significant relationship with depression measure, and all the subscales except one correlated with Difficulties in Identifying Feelings component of alexithymia. Conclusions The DERS proved to be an adequate measure of clinically relevant dimensions of emotional dysregulation in chronic pain patients.