Background: The development and resolution of an inflammatory process is regulated by a complex interplay among cytokines that have pro and anti-inflammatory effects. Regulatory mechanisms that control the production of cytokines include genetic polymorphism in particular promoter/leader region. Polymorphisms may directly or indirectly affect the binding of transcriptional factors, consequently increasing or decreasing the production of mRNA, thus regulating cytokine production. We aimed to determine the polymorphism of tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) genes in chronic hepatitis C patients. Methods: 40 HCV RNA positive patients were included in the present study conducted during 2006-2008. 25 healthy controls were also included. Genomic DNA was extracted by using Q1A amp DNA blood kit protocol according to manufacture's instruction and desired fragment was amplified by using the primer's of Vidigal et al 2002.