A 66-year-old man with hepatocellular carcinoma (HCC) and suspicion of lung metastasis consulted us because of an abnormal chest shadow as seen on a radiograph. He had been treated with sorafenib for 2 months. A chest CT scan showed cavitating nodules in the left upper lobe that were present before therapy with sorafenib, and infiltrative shadows in the subpleural areas of the right upper lobe. The shadows were diagnosed, at least in part, as pulmonary tuberculosis by using a nucleic acid amplification test for Mycobacterium tuberculosis in the sputum that yielded a positive result. Treatment with antituberculosis drugs resulted in a good clinical response. However, the patient died of HCC. We concluded that the nodule in the right upper lobe was old pulmonary tuberculosis, because it did not change during the course of the disease and because the cavities in the left upper lobe were active lesions. Sorafenib is a molecularly targeted agent that has been proven effective for treating advanced HCC with extrahepatic metastasis. It may also cause necrosis within lung metastases as an anti-tumor effect. Therefore, pulmonary tuberculosis, including reactivation, should be considered in the differential diagnosis when treating a patient with sorafenib.