Objectives Our main goal was to provide the psychometric properties of the Spanish version of the Dimensional Obsessive-Compulsive Scale (DOCS) in a non-clinical sample (n = 237) and in adult patients with Obsessive-Compulsive Disorder (OCD) (n = 110). We also examined the association between OC symptom dimensions and obsessive beliefs. Methods The psychometric properties involved four steps: reliability, structural validity, convergent and discriminant validity and diagnostic sensitivity. Linear regression analyses were used to assess the associations between OC symptoms and obsessive beliefs. Results Exploratory and confirmatory factor analyses replicated the original four-factor structure in both samples. The DOCS showed good performance in terms of internal consistency, test-retest reliability and convergent validity in both samples. The DOCS showed better diagnostic sensitivity than another self-report instrument of OC symptoms, the Obsessive-Compulsive Inventory Revised. Findings of the relationship between obsessive beliefs and OC symptoms revealed that certain obsessive beliefs predicted specific OC symptom dimensions. Conclusions The Spanish version of the DOCS has similar psychometric properties than the original English instrument, although its performance is somewhat better in OCD patients than in students. It will be important to ascertain its ability to discriminate OCD from other associated disorders. © 2014 Elsevier Inc.