The main organs are attacked by the disease is pulmonary tuberculosis, which is known as pulmonary tuberculosis. Pulmonary TB disease is a chronic disease that poses a health problem in the world, including Indonesia. One characteristic of pulmonary TB is attacked in the presence of spotting objects (infiltrates) in the lungs. To detect the presence of pulmonary infiltrates there is one of them can be done with the results of x-ray examination of the thorax. To produce a good image of the thorax of the results of x-ray that can be done with digital image processing. So that the image processing results which can be used to identify infiltrates in lung tissue tuberculosis. Image processing is intended to clarify the observations the existence of infiltrates on x-ray image of the thorax. In this study would be conducted object identification process infiltrates in patients with tuberculosis by the process of mathematical morphology. While the result is an image that can display white spots that form infiltrates and can determine the position of the infiltrate. Keywords: tuberculosis, infiltrate, x-ray thorax, morphology