Purpose:To assess the prevalence and associated factors of unprotected anal intercourse among Iranian male heterosexual Intra-Venous Drug Users (IDUs). Methods: In a cross-sectional study 360 male heterosexual IDUs were sampled from streets of eight different geographical parts of Iran. Variables such as socio-demographics, HIV knowledge (10 items), and HIV attitude (16 items) were entered to a logistic regression to determine the predictors of unprotected anal intercourse during the past month. Results: From all, 20.8% reported unprotected anal intercourse during the past month. HIV knowledge was not significantly different among IDUs with and without unprotected anal intercourse. High age [odds ratio (OR)D0.954, 95% confidence intervals (CI)D0.916– 0.992] was associated with a lower likelihood of unprotected anal intercourse, while being not married (ORD2.301, 95% CID1.151–4.601), and high perceived HIV risk (ORD1.776, 95% CID1.376–2.290) were associated with a higher likelihood of unprotected anal intercourse. Conclusion: Although the results might not be generalizable to all Iranian IDUs, this study findings may still be helpful for design and implementation of public health programs in Iran to prevent sexual transmission of HIV through IDUs.
