A cross sectional study was conducted among 280 injecting drug users (IDUs) in three districts of Quang Nam province in 2013 in order to indentify the prevalence of HIV and behavioral risk factors of HIV infection in this group. The results showed that prevalence of HIV among this group was 6.4 percent. Behavioral risk factors of HIV infection among injecting drug users included sharing needles and syringes and sharing drug pots for previous 6 months, 33.2 percent, and 47.5 percent, respectively. In addition, low frequency of using condoms during have sexual contacts with female sex workers was another behavioral risk factor of HIV infection among the population: 24.6 percent for sometimes and 9.2 percent have never used condoms. Health interventions, including health promotion and health education, should be focused on this group. The study results also provides some suggestions as to enhance direct communication for IDUs, implementing harm reduction programs such as needles and syringes, condom programs and the establishment of a methadone treatment facility in Tam Ky city.