1.1. Background: Tripterygium Hypoglaucum Hutch (THH), extracts of a Chinese medicinal plant, shows immunosuppressive function and has been used in China for decades to treat autoimmune and inflammatory conditions. This retrospective study aimed to determine long-term efficacy of THH in treating patients with BD-associated uveitis. Methods:Thirty-two patients with BD-associated uveitis resistant to conventional treatment were enrolled. Extracts of THH, 33mg/kg daily, were administered orally along with prednisone. The observation period was 46.8 months. Results:A positive response to THH therapy was observed in 87.5% of patients, showing 62.5% complete remission of uveitis and 75.8% achieved visual acuity maintained or improvement. THH was effective to reduce the incidence of ocular relapse (from 2.9 to 0.4 per yr, p<0.0001) and the dose of corticosteroid (from 22.3 to 11.6 mg daily, p<0.01), with beneficial effects on extraocular manifesta-tions. Side effects are rare and dose-dependent. Conclusion:THH therapy has significant potential in treating patients with sight-threatening BD-associated uveitis, showing beneficial effects on improvement of visual acuity, long-term remission and extraocular lesions of BD.