Idiopathic pulmonary fibrosis is a chronic, progressive interstitial pneumonia of unknown cause. It occurs primarily in older patients and is limited to the lungs. The prognosis is poor with a median survival of 2-3 years after diagnosis. The diagnosis is based on a definite pattern of usual interstitial pneumonia on high resolution computed tomography or specific combinations of radiological and histopathological patterns. All patients should be evaluated for lung transplantation, and treatment with the anti-fibrotic drug pirfenidone is recommended for patients with a forced vital capacity > 50% and a lung diffusion capacity > 35%.