Due to their shared transmission route, hepatitis B virus (HBV) or hepatitis C virus (HCV) co-infections can be observed in human immunodeficiency virus (HIV)-infected cases and are associated with more severe clinical courses. The detection of HBV DNA despite HBV surface antigen (HBsAg) seronegativity is defined as occult HBV infections. According to the current seroepidemiological data, Turkey is classified as an intermediate HBV, low HIV endemic region. Occult HBV infections have previously been reported from Turkey but has not been investigated previously in HIV infected cohorts. The aim of this study was to identify occult HBV infections in HIV-infected persons. Twenty-eight HIV-positive cases followed-up at Hacettepe University Hospital, Infectious Diseases Unit were included in the study after informed consent. For the detection of HBsAg, anti-HBs and anti-HCV, commercial ELISA tests (Architect System, Abbott Diagnostics, USA) were employed. Absolute CD4+ and CD8+ T-cell counts were determined via flow cytometry. HIV viral load was calculated via COBAS TaqMan HIV-1 Real-time PCR (Roche Diagnostics, USA) and the presence of HBV DNA was evaluated via COBAS Taq Man HBV Real-time PCR (Roche Diagnostics, USA), in addition to a nested PCR assay targeting HBV S gene. The mean age of the study group was 43.2 (range between 27-65) years, 64.3% (18/28) of them were males and the mean duration of HIV infection was 4.2 (2-11) years. Mean CD4+ ve CD8+ T-cell counts were 414 +/- 267 cells/mm(3) and 854 +/- 293 cells/mm(3), respectively. Twenty-six (92.8%) cases were under highly-active anti-retroviral therapy at the time of the study, 88.5% of which included HBV-active drugs (lamivudine or tenofovir). HIV RNA were found negative in 11(39.3%) patients, of those nine (81.8%) were the cases who treated with HBV-active antiretroviral therapy. HBsAg were negative in all of the 28 patients, while the positivity rates of anti-HBs and anti-HCV were 39.3% (11/28) and 3.6% (1/28), respectively. All samples were negative for HBV DNA via the commercial real-time PCR and in-house nested PCR assays. The absence of occult HBV in the study group may indicate the absence of occult HBV or suppression of viral replication due to the anti-retroviral therapy. In conclusion, further large-scale studies are required to fully understand the impact of occult HBV in HIV-infected patients in Turkey.