Background; Hepatitis is a general term meaning inflammation of the liver and can be causedrnby different viruses. Hepatitis B virus (HBV) is DNA virus causing hepatitis in human. Thernprison setting has been shown to be a high risk environment for blood borne viral infections likernhepatitis B virus infections. The aim of this study was to assess the prevalence and associatedrnfactors of hepatitis B virus infections among prison inmates in Kality Prison.rnObjectives: Determining the prevalence and associated factors of HBV infections amongrnprison inmates at Kality Prison in Addis Ababa, Ethiopia.rnMethods: A cross-sectional study was conducted from January 2016 â€“ October 2016 data onrnsocio demographic and HBV risk factors were collected using a semi-structured questionnaire.rnTwo ml of venous blood samples were collected and serum was tested for hepatitis B virusrninfections using commercially available rapid test kits. Data were analyzed using SPSS versionrn21.0. Logistic regression analysis was used and a P value < 0.05 was considered statisticallyrnsignificant.rnResults: A total of 457 prison inmates, 347 males and 100 females, with a mean age of 37.9rnyears were participated. Twenty-two participants (4.8%) were positive for hepatitis B surfacernantigen. Our study revealed that inmates who had an experience of sharing sharp materials werernabout 2.6 times (AOR =2.59; 95% CI: 1.04-6.43) at higher risk of hepatitis B seropositive,rncompared to inmate who had no such experience. On the other hand, prison inmates who hadrnhistory of tooth extraction in the past were also about 2.8 times (AOR = 2.83; 95% CI: 1.11-rn7.22) at the risk compared to those who had no such experience.rnConclusion: This study found that prison inmates had intermediate prevalence of hepatitis Brnvirus infections. Based on the findings of this study sharing of sharp materials and history ofrntooth extraction are the most important risk factors for acquiring HBV infection in this prison.rnThus, improving the individual education and expanding the HBV vaccination coverage mayrnreduce the rate of infection in this subpopulation.rnKey words: Hepatitis B virus , Prison.