After nine weeks of combination therapy with recombinant interferon-alpha and ribavirin for chronic hepatitis C a 62-year old woman complained of a dry cough and exertional dyspnea. An elevated erythrocyte sedimentation rate was noticed. Prior to treatment chest X-rays and physical examination revealed no pulmonary abnormalities. Inhalative steroids did not improve the symptoms and afer 12 weeks treatment chest X-ray and computed tomography showed bilateral reticonodular lung infiltration suggesting a diagnosis of interstitial pneumonitis. Cough and dyspnea resolved and abnormal lung shadows were reversible within two months following discontinuation of interferon-/ribavirin treatment. In the Japanese literature there are similar reports on pneumonitis occurring during high-dose IFN-alpha and concomitantly Chinese herbal medicine treatment. To our knowledge this is one of the first cases of interstitial pneumonitis due to combination therapy with IFN-alpha and ribavirin in chronic hepatitis C reported in the western world.