Abstract: Background and Aims: Substance users are at high risk of viral (HBV and HCV) and alcoholic liver disease leading in some to progressive fibrosis and cirrhosis. Users in rehabilitation programs often lack information about health risks related to substance use and ways for prevention and treatment and often postpone medical workup and treatment. The aims were: 1. To improve knowledge and awareness about the epidemiology, mode of acquisition, natural history, diagnosis and treatment of chronic viral hepatitis B and C in persons participating in substance use rehabilitation programs in southern Switzerland. 2. To identify users with liver disease and fibrosis or cirrhosis using ALT and Fibroscan testing, and 3. To offer personalized counseling on diagnostic workup and treatment for persons with significant fibrosis or cirrhosis in order to prevent progression to cirrhosis and its complications. Methods: Substance use rehabilitation programs were contacted and offered an educational event, held by an MD, with information on epidemiology, mode of acquisition, natural history, diagnosis and treatment of chronic alcoholic and viral hepatitis B and C. Participants interested were given the possibility to undergo ALTtesting, Fibroscan® testing as well a consultation with a hepatologist, free of charge. Results: Eleven Institutions were involved in the program, 7 offering residential and 4 daytime rehabilitation programs. A total of 136 users and 22 health care workers attended the educational sessions. 82 of whom (60.3%) participated in the ALT/Fibroscan screening program. The mean age was 43.9 years (65 male and 17female users). 45% had abnormal ALT levels. The mean was 89.6 IU/ml. Only 17% had normal liver elasticity, 83% had abnormal values compatible with fibrosis assessed by Fibroscan (>4.0 KPa). 21.9% had at least moderate (F2-F4) fibrosis (>8.0 KPa) and 10.9% had values indicating the presence of cirrhosis (>16 KPa, F4).The running costs in terms of personnel and materials of this pilot program were slightly more than 100 Swiss Francs per participant. Conclusions: The results confirm a high burden of liver disease in substance users in rehabilitation programs in our region. The interest and adherence to the program was excellent with 60.3% of those participating in the educational event undergoing voluntary ALT and Fibroscan® testing followed by counseling. Significant liver disease was found in more that 4/5 of the participants. More than 10% had results compatible with cirrhosis. Similar programs can be adapted to other high-risk settings for liver disease at reasonably low costs.