Background: Hepatitis B (HBV) and Hepatitis C (HCV) viruses are hepatotoxic viruses thatrnspread mainly through contaminated blood and blood products, sexual contact and contaminatedrnneedles. HBV and HCV infection share similar transmission routes and therefore co-infection isrncommon. These viruses are prevalent in different parts of the world including Ethiopia. Five andrnthree point three percent of world population have been infected with HBV and HCVrnrespectively. The prevalence of HBV is 2.0% in USA, 8.0-20.0% in South- East Asia, thernprevalence of HCV 4.8% in Pakistan, 3.2% in china and 22% in Egypt. In Ethiopia, there is lackrnof data on the prevalence of HBV and HCV and globally concerning to psychiatric patients.rnObjective: The aim this research was to determine the Magnitude of HBV and HCV infectionrnamong psychiatric patients.rnMethods: A Cross-sectional study was conducted in the study site among psychiatric patients.rnStructured questionnaires were used to collect information pertaining to socio demographicrnfactors including history of mental illness, and associated factors for HBV and HCV infection.rnBlood specimen was collected and serum was separated to determine hepatitis B surface antigenrn(HBSAg) and anti-HCV antibody by Enzyme linked immunosorbent Assay (ELISA). Data wasrnanalyzed using SPSS version 20 software. We have used descriptive statistics for some variables.rnMoreover, bivariate and multivariate analysis was applied. The Odds ratio with 95 % CI wasrnused to assess the risk factors. P value less than 0.05 was taken as statistically significant.rnResult: A total of 384 participants who have Psychiatric problems were participated in thisrnstudy, where 208 (54.2%) of them were males. The age distribution ranges form 20-70 years.rnThe overall burden of HBsAg and HCV antibody was 20.3% and 14.3 % respectively. History ofrntattooing of body and blood transfusion were found to be statistically significance with HBVrnvirus infection and history multi sexual partners with HCV infection.rnConclusion: Magnitude of HBV and HCV is high among Psychiatric patients and special effortsrnshould be taken by the hospitals and other stakeholders to investigate the real source of HBV andrnHCV infection among the psychiatric and other mentally ill people in order to addressrnappropriate intervention measures.rnKey wordsá¡ HBV, HCV, Magnitude