Introduction & Objective: According to WHO report, there are more than 40.3 million people infected with HIV worldwide. Detection of HIV-infected people in each community helps to control and prevent the infection. This study aimed to evaluate the prevalence of HIV infection among high-risk groups in Kohgiloyeh and Boyerahmad province in Iran. Materials & Methods: This was a cross-sectional study which was conducted in 2009 in Kohgiloyeh and Boyerahmad province in Iran. High-risk groups for HIV were the subjects of this study. Blood samples were taken from 2009 people from Boyerahmad, Gachsaran, and Dehdasht and tested by ELISA for anti-HIV1/2 antibodies. Demographic features of participants were recorded using a questionnaire during sample collecting. Collected data were analyzed by SPSS version 13 software. Results: From 2009 subjects, HIV antibody was detected in 36 (1.8%) of cases. High prevalence of infection (3.2%) was seen in 31-40 years age group. The rate of infection was higher in males compared to females. Unemployed people were found to be the main victim of the disease. The highest rate of infection was seen in Gachsaran in comparison to other townships. Conclusion: Findings of this study demonstrated that HIV infection is prevalent in high-risk groups in Kohgiloyeh and Boyerahmad province and control measurements should be implemented to prevent the distribution of the infection.