BACKGROUND: To identify risk factors associated with benign essential blepharospasm (BEB) with reference to hemifacial spasm (HFS). Persons with BEB and HFS experience similar physical symptoms, yet the two disorders have different etiologies. METHODS: Patients with BEB (n = 159) or HFS (n = 91) were identified from two large neuro-ophthalmology clinics. Demographic, medical, behavioral, and psychological characteristics were obtained from chart review and a telephonic survey questionnaire. RESULTS: The average age of BEB and HFS was 66 years. Most patients in both groups were retired, white, and female. BEB patients were more than two times as likely to meet the diagnostic criteria for generalized anxiety disorder than HFS patients (odds ratio, 2.13; 95% confidence interval, 1.22-3.72).There was no difference between the two groups regarding demographics, smoking, a family history of dystonia, Parkinson disease, Bell palsy, Tourette disorder, obsessive compulsive symptoms, history of head trauma, alcohol use, or caffeine consumption. CONCLUSIONS: As compared to HFS, BEB was significantly more often associated with generalized anxiety disorder. Given the similarity of other clinical features of these two disorders, it is reasonable to conclude that anxiety is a cause not a consequence of BEB. Contrary to previous studies, BEB was not associated with obsessive-compulsive symptoms, head trauma, Parkinson disease, Bell palsy, Tourette disorder, or lack of smoking. © 2005 Lippincott Williams & Wilkins.