The term orthorexia nervosa (ON) was coined to describe altered thoughts and behaviours related to healthy eating. The prevalence of ON was found to scale up to almost 90% among high-risk populations (ballet dancers, athletes, and health workers). ON seem to share psychopathological aspects with both Eating Disorders (ED) and Obsessive-Compulsive Disorder (OCD). The aim of the study was to analyse the frequency and intensity of ON symptoms among subjects diagnosed with OCD, hypothesising that they would be higher than in two control groups (subjects with anxiety-depressive disorders and general population).