Background: GB virus C (HGV) is classified as pegivirus of the family flaviviridae.  It is a positive sense single stranded RNA virus. Due to the shared transmission modes with HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV), co-infection with HGV, are common among people infected with HIV, HBV and/or HCV. Objective:  Determination of the incidence of HGV in chronic liver diseases in frequent blood donors and hemodialysis patients with or without HIV infection and influence of HGV on the course of HIV infection. Materials and methods: In the present study, 60 patients were divided into 2 equal groups as frequent blood donors group and hemodialysis group. They were mainly between 40 - 60 years old. 10% were females and 90% were males in blood donors group. 26.7% were females and 73.3 % were males in hemodialysis group. They were suffering from chronic liver diseases. They were investigated to study the incidence of HGV in chronic liver diseases with or without HIV infection and influence of HGV on the course of HIV infection. This was in addition to 20 persons who were not exposed to major risk factors of hepatitis as a control group. All members of the study were subjected to complete history and clinical examination as well as laboratory investigations for estimation of CD4 cells count, HBsAg by ELISA, HCV Ab by ELISA, HIV Ab by ELISA and HGV RNA using RT-PCR. Tests of liver functions included serum bilirubin (total and direct), ALT, AST, alkaline phosphatase (ALP), total proteins, and albumin. Results: Liver biochemical profile showed a significant  relations with CD4 cells count where CD4 cells count decreased by increasing of ALT(SGPT), AST (SGOT), alkaline phosphatase (ALP), total bilirubin and increased by increasing serum albumin. Regarding the CD4 cells count and PCR for HGV, patients with HGV have a significant higher CD4 cells count than patients without HGV.  Patients with both HIV and HGV have a significant higher CD4 cells count than patients with HIV without HGV.  Results indicated that, out of 30 patients of frequent blood donors (BD) group, 28 (93.3%) were negative for HIV, and 2 (6.7%) were positive for HIV. Concerning hemodialysis group (HD), out of 30 patients, 26 (86.7%) were negative for HIV, and 4 (13.3%) were positive for HIV. In case of blood donors group, out of 30 patients, 26 (86.7%) were negative for HGV, and 4 (13.3%) were positive for HGV. Out of 30 patients of hemodialysis group, 26 (86.7%) were negative for HGV, and 4 (13.3%) were positive for HGV.  Conclusions: HGV infection has a moderate frequency among hepatichemodialysis and frequent blood donors.  HIV co-infection with HGV was associated with significantly high CD4 cell count suggesting a beneficial effect of HGV infection on HIV co-infected patients.