Background. We report the safety and efficacy of transbronchial biopsy for endotracheal lesions of primary pulmonary lymphoma (PPL) in the clinical setting. Case. The patient was a 59-year-old man who presented with abnormal shadows on chest radiography at an annual health examination. Chest computed tomography (CT) revealed granular and linear shadows in the right upper lobe. Approximately 2 years passed with the shadows improving and exacerbating; then a 60-mm sized tumor shadow appeared at the same site, suggesting severe stenosis of the central bronchus near the tumor. Bronchoscopy revealed a paving stone-like white elevated lesion obstructing from outside the lower part of the trachea to the entrance of the right main bronchus. A biopsy was not performed because the right main bronchial lumen was highly constricted and the procedure was considered to be associated with a high degree of risk. CT-guided biopsy was performed at a later date, leading to the diagnosis of diffuse large B-cell lymphoma. Chemotherapy was started for the patients, which resulted in complete remission. Conclusion. This is a case of PPL that was diagnosed by CT-guided biopsy. For the histological diagnosis of central airway lesions in PPL, it is necessary consider the safety and accuracy of biopsy methods with reference to the lumen findings.