en Infectious Disease Infectious Disease Original Research Original Research <strong>Background: </strong>Acquired Immunodeficiency Syndrome (AIDS) is one of the most important health challenges worldwide. Moreover, the prevalence of the Human Immunodeficiency Virus (HIV) infection differs among Iranian prisoners and the general population. The present study aimed to identify the patterns of HIV-related high-risk behaviors in male prisoners.<br> <strong>&nbsp;&nbsp; Methods:</strong> In this cross-sectional study, 2832 inmates were examined for HIV-related high-risk behaviors. The required data were collected using a questionnaire on high-risk behaviors, including a history of heterosexual and homosexual intercourse, and a history of drug use disorders. A Latent Class Analysis (LCA) was performed to analyze the obtained data in WinLTA software.<br> <strong>&nbsp;&nbsp; Results:</strong> Five latent classes were defined for the male prisoners, as follows: low-risk (20%), moderate-risk (23%), Injection Drug Use (IDU) (8%), heterosexual intercourse/methamphetamine use (38%), and high-risk (11%). The LCA results revealed that high-risk sexual behaviors, IDU, and sharing injection equipment in prisons significantly influence the classification. The obtained data suggested that a history of imprisonment was not frequent in class 2 (OR=1.0033, %95CI:0.9936&ndash;1.01) and class 4 members (OR=1.0053, %95CI:0.9929&ndash;1.0179). However, it was more prevalent in class 3 (OR=1.0164, %95CI:1.0068&ndash;1.0262), and 5 (OR=1.0211, %95CI:1.0129&ndash;1.0293). Heterosexual contact had the highest prevalence (75%) in this regard. The results showed that the lowest prevalence of high-risk behaviors was associated with morphine use (0.3%). Among illicit drugs, methamphetamine was the most prevalent drug (42%) in the studied subjects.<br> <strong>&nbsp;&nbsp; Conclusion:</strong> The present study indicated a high prevalence of high-risk sexual behaviors and methamphetamine use in the investigated participants. We observed the co-occurrence of HIV-related high-risk behaviors in male prisoners. Thus, providing safe sex education for prisoners is highly recommended. It is also necessary to pursue care programs about IDU as a key risk factor for HIV transmission in prisons. Latent class analysis, Male prisoners, Male non-prisoner, Human Immunodeficiency Virus (HIV) 747 751 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-5389-1&slc_lang=en&sid=1 Jalal Ale-Ebrahim jalal.aleebrahim@gmail.com 200319475328460064311 200319475328460064311 No Department of Epidemiology, School of Health, Iran University of Medical Sciences, Tehran, Iran Leila Janani leila_janani@gmail.com 200319475328460064312 200319475328460064312 No Department of Biostatistics, School of Public Health, Iran University of Medical Sciences, Tehran, Iran Seyed Ahmad SeyedAlinaghi s_a_alinaghi@yahoo.com 200319475328460064313 200319475328460064313 No Iranian Research Center for HIV/AIDS, Iranian Institute for Reduction of High-Risk Behaviors, Tehran University of Medical Sciences, Tehran, Iran Behnam Farhoudi b_farhoudi@yahoo.com 200319475328460064314 200319475328460064314 No Social Determinants of Health Research Center, Amir-Almomenin Hospital, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran Abbas Abbasi-Ghahramanloo abbasi.abbas@yahoo.com 200319475328460064315 200319475328460064315 No Department of Public Health, School of Health, Ardabil University of Medical Sciences, Ardabil, Iran Mansoor Sajadipour sajjadi.mansour@yahoo.com 200319475328460064316 200319475328460064316 No Tehran University of Medical Sciences, Tehran, Iran Seyed Abbas Motevalian motevalian.a@iums.ac.ir 200319475328460064317 200319475328460064317 Yes Research Center for Addiction and High-Risk Behaviors (ReCARB), Psychosocial Health Research Institute, Iran University of Medical Sciences, Tehran, Iran