The diagnosis and treatment of mycobacterial diseases are very important clinical issues. Among mycobacterial diseases, pulmonary tuberculosis remains an important cause of morbidity and mortality throughout the world. Pulmonary tuberculosis demonstrates a variety of clinical and radiological features. In addition, the prevalence of Mycobacterium avium complex (MAC) has increased, especially in elderly women without underlying diseases. Clinically, there is a significant difference between tuberculosis and atypical mycobacterium infection in terms of the infection control measures adopted and the choice of treatment. Therefore, it is very important to know the characteristic radiological findings of mycobacterial diseases. In the present review, key radiological points for diagnosing mycobacterial diseases are discussed.