This study is aimed at investigating obsessive-compulsive disorder (OCD) in three groups of patients matched for age and gender; namely, focal dystonia (FD), hemifacial spasm (HFS), and healthy-control subjects (HC). All subjects were investigated with the Structured Clinical Interview for DSM-I, the Hospital Anxiety and Depression Scale, the Symptom Checklist-90, the Yale-Brown Obsessive-Compulsive Scale, and the Structured Clinical Interview for Obsessive-Compulsive Spectrum Self-Report, Lifetime Version (SCI-OBS-SR-LT). The prevalence of OCD was significantly higher in both FD and HFS than in HC participants. On the SCI-OBS, HFS patients showed higher scores than FD or HC for "contamination" and "aggressiveness." Despite the different pathophysiology, OCD is highly represented in both FD and HFS, with different thematic content characterizing the two conditions.