Idiopathic bronchiolocentric interstitial pneumonia is one of idiopathic interstitial pneumonia, which has a relatively aggressive course and poor prognosis. It is characterized by diffuse centrilobular nodules radiologically with mainly bronchiolocentric inflammation and fibrosis associated with patchy alveolitis lacking interstitial granuloma histologically. This disorder is a recently classified disease category, and to our knowledge, there is no case report in Korea. We present a case of idiopathic bronchiolocentric interstitial pneumonia. A 62-year-old man presented with exertional dyspnea with a 1 month duration. The radiological findings showed extensive centrilobular lesions at both lungs. The surgical lung biopsy specimen demonstrated a centrilobular inflammatory process with small airway fibrosis and inflammation partially radiating into the interstitium. Therefore, the patient was diagnosed with idiopathic bronchiolocentric interstitial pneumonia. He was treated with immunosuppressants including steroids and azathioprine. However, his symptoms did not improve and he expired 7 months later due to an acute exacerbation of the interstitial pneumonia and probable infectious pneumonia.