This study reports the factorial structure and psychometric properties of a Spanish version of the Padua Inventory (PI) in a sample of 863 undergraduate students, 55 patients with Obsessive-Compulsive Disorder (OCD), and 20 patients with other anxiety disorders (OAD). A Principal Components Analysis suggested a 4-factor structure, which was comparable but not identical to that found in other versions of the PI involving non-clinical samples. The PI sub-scales showed good internal consistency, test-retest reliability, as well as convergent and discriminant validity. The “Washing” sub-scale of the PI failed to separate OCD and OAD patients, although this may have been due to small sample sizes. It is suggested that a revised version of the PI should include symptoms that are not currently represented in the scale, such as hoarding obsessions and compulsions.