Background and Objectives: The aim of this study is to evaluate the efficacy of prostaglandin I2 (PGI2) in the patients with chronic nonspecific vertigo using questionnaires of dizziness handicap inventory (DHI) and vertigo symptom scale (VSS). Materials and Methods: Forty two patients with chronic nonspecific vertigo from May to December 2010 were enrolled in this study. We administered Berast (synthetic PGI2, beraprost sodium) 2 tablets (0.04 mg) twice a day to patients. Before and after 2, 4 weeks the end of administration patients underwent DHI and VSS for evaluation of state of the vertigo. Results: Twenty four of 42 patients completed this clinical trial. Mean DHI scale score decreased significantly from 23.00 (±21.75) to 17.75 (±19.78) (p=0.004). All DHI subscales, physical, functional, and emotional factors, decreased after treatment of prostaglandin I2. VSS scale also showed significant decrease from 3.63 (±2.55) to 2.50 (±2.95) (p=0.044). Conclusion: Prostaglandin I2 may be one of the treatments to improve symptoms in the patient s with chronic nonspecific vertigo.