Back ground: Prevalence of Hepatitis B infection in HIV infected patients in a Tertiary care Hospital. Materials &Methods: A retrospective study was undertaken to find prevalence of Hepatitis B infection (HBV) in Human Immunodeficiency Virus (HIV) infected patients who were attending anti retroviral therapy (ART) at our Medical College. Results: A total of 1834 serum samples were processed during January 2010 to September 2011. Male to Female ratio 1.13 in HBV in HIV infected patients. The result revealed that co-infection of HBV and HIV is 6.32 % (116/1834). Conclusion: Child hood and adult HBV infection can be prevented by vaccination. Vaccine preventable Hepato Cellular Cancer (HCC)