To clarify features of lung cancer in patients with tuberculosis sequelae, we analyzed data on 15 cases (5.1%) who were diagnosed with lung cancer before death among 294 deceased cases with tuberculosis sequelae at our hospital. There were 12 men and 3 women, with a mean age of 64 years. Most of the 15 patients had pulmonary dysfunction, and 4 had received home oxygen therapy. All 12 men had a history of smoking, and 10 of them had squamous cell carcinoma of the lung. There was no definite correlation between the locations of the tuberculosis lesion and those of lung cancer lesion on chest X-rays. Twelve patients had had thoracoplasty for tuberculosis, and in 6 of these patients the lung cancer occurred in the same lung. Lung cancer was apt to be diagnosed in an advanced stage. However, in patients who received home oxygen therapy, diagnosis had been made at an early stage because of the frequent chest X-ray follow-up. We conclude that lung cancer is an important complication in patients with tuberculosis sequelae, and early diagnosis of lung cancer by careful follow-up is essential in the care of cases with tuberculosis sequelae who have poor pulmonary function and/or systemic conditions.