Injecting drug use which is the prime contributor to the overall HIV epidemic in a country is rapidly spreading in Bangladesh. Although Bangladesh is experiencing lower rate of HIV prevalence, risk behaviors like needle sharing and unprotected sex among IDUs facilitate to build up a ‘critical mass’ of infections within needle sharing and sexual networks, from where HIV can be spread. The objective of this study was to investigate the current knowledge and awareness of IDUs about the risk of HIV infection. This is a cross-sectional study among 60 IDUs from three drop-in-centers of Dhaka, the capital of Bangladesh from June to August of 2007. Among the 60 respondents, 58(96.7%) heard about HIV/AIDS. 55(91.7%) IDUs knew that unprotected sex is a cause of transmission of HIV. 52(86.7%) IDUs mentioned about needle sharing. 35(58.4%) IDUs share needle during injecting drug of which 31(51.7%) admitted that it is not safe to share. IDUs are reluctant to apply their knowledge about HIV into the practice of drug use which put them under tremendous risk of acquiring HIV infection.