PURPOSE: To evaluate chest CT features of pulmonary tuberculosis mimicking lung malignancy. MATERIALS AND METHODS: We retrospectively reviewed chest CT findings for 76 consecutive patients (21-84 years, average: 63 years; M : F = 30 : 46) who underwent an invasive diagnostic procedure under the suspicion of lung cancer and were pathologically diagnosed as pulmonary tuberculosis by bronchoscopic biopsy (n = 49), transthoracic needle biopsy (n = 17), and surgical resection (n = 10). We categorized the chest CT patterns of those lesions as follows: bronchial narrowing or obstruction without a central mass-like lesion (pattern 1), central mass-like lesion with distal atelectasis or obstructive pneumonia (pattern 2), peripheral nodule or mass including mass-like consolidation (pattern 3), and cavitary lesion (pattern 4). CT findings were reviewed with respect to the patterns and the locations of the lesions, parenchymal abnormalities adjacent to the lesions, the size, the border and pattern of enhancement for the peripheral nodule or mass and the thickness of the cavitary wall in the cavitary lesion. We also evaluated the abnormalities regarding the lymph node and pleura. RESULTS: Pattern 1 was the most common finding (n = 34), followed by pattern 3 (n = 23), pattern 2 (n = 11) and finally, pattern 4 (n = 8). The most frequently involving site in pattern 1 and 2 was the right middle lobe (n = 14/45). However, in pattern 3 and 4, the superior segment of right lower lobe (n = 5/31) was most frequently involved. III-defined small nodules and/or larger confluent nodules were found in the adjacent lung and at the other segment of the lung in 31 patients (40.8%). Enlarged lymph nodes were most commonly detected in the right paratracheal area (n = 9/18). Pleural effusion was demonstrated in 10 patients. CONCLUSION: On the CT, pulmonary tuberculosis mimicking lung cancer most commonly presented with bronchial narrowing or obstruction without a central mass-like lesion, which resulted in distal atelectasis and obstructive pneumonitis.