The diffuse nodular lung lesion has a diagnostic problem and should be made differential diagnosis. A chest X-ray of 62-year-old male patient with dyspnea showed small-sized scattered multinodular lesion on entire lung field. Bronchoalveolar lavage and transbronchial needle aspiration showed the non-specific findings, so open lung biopsy was done and revealed bronchioloalveolar cell carcinoma.