OBJECTIVES: To demonstrate the health economic impact of OM-85, a bacterial lysates based immunostimulant, for its approved indications in China. METHODS: A cost effectiveness decision tree model was constructed. The model compared OM-85 with the best supportive care therapy for the treatment of chronic bronchitis and rhinosinusitis in Chinese population. Clinical efficacy and adverse events (AE) data were included in the model based on a thorough literature review. All localized direct treatment costs, including drug cost, AE costs, and medical treatment costs for underlining diseases were included from Chinese payer perspective for both OM-85 and best supportive care group. A Key Opinion Leaders (KOL) survey was conducted to validate the local treatment costs. A total of 20 senior physicians specialized in respiratory, ENT, allergy, and immunology fields were selected from tertiary hospitals in Beijing, Shanghai, Guangzhou, Hangzhou, Chongqiong, Chengdu and Wuhan to form an representative geographic sample. All physicians were requested to complete a questionnaire which included the clinical management of acute exacerbation of chronic bronchitis and rhinosinusitis in China, the management of OM-85 related AEs, and the attitude towards the clinical efficacy and effects of OM-85. Incremental cost effectiveness ratio (ICER) was calculated based on the above efficacy and cost information. RESULTS: The results indicate that, when compared with best supportive care therapy,OM-85 is a dominant therapy (with better clinical efficacy and lower overall costs) in Chinese population for the clinical management of chronic bronchitis and rhinosinusitis One way sensitivity analyses were performed and the ICER result was demonstrated to be robust. CONCLUSIONS: Based on its clinical efficacy in preventing acute exacerbations of chronic bronchitis and rhinosinusitis, OM-85, when compared with standard care therapy, proved to be a dominant therapy (better clinical efficacy and lower overall costs) in Chinese population for the clinical management of chronic bronchitis and rhinosinusitis.