A 72-year-old-man was admitted to our hospital because of an abnormal chest shadow. Histological findings from video-assisted thoracoscopic surgical lung biopsy showed desquamative interstitial pneumonia (DIP). Although DIP is classified as the idiopathic interstitial pneumonias (IIPs), it is widely accepted that the cause of DIP might be associated with cigarette smoking. The patient had chronic hepatitis C virus (HCV) infection; however he did not have a history of active or passive smoking. An immunologic response to HCV infection may have a role in the pathogenesis of DIP in patients with chronic HCV. DIP should be included in the differential diagnosis of diffuse parenchymal lung disease in patients with HCV infection.