Hepatitis C virus is a common infectious agent, it is estimated that 3 % of the world population are infected with HCV, extrahepatic immunologic abnormalities have been shown to occur frequently in patients with chronic HCV infection, interstitial lung fibrosis is one of the extrahepatic manifestation of HCV infection, this study aimed to investigate the relation between HCV infection and IPF using pulmonary function tests. This work included 30 patients, ten healthy subjects were enrolled in the study as control group.We concluded that any patient with HCV infection particularly those with positive cryoglobulinaemia needs careful evaluation with PFT and HRCT.