Two pneumonic foci are described on lung radiographs as a sign of lung infection, such as bronchitis or pneumonia. Lung imaging is an important tool in the diagnosis of lung diseases, and the description “two pneumonic foci” may appear on the examination report of some patients. These foci are most commonly seen in lung diseases caused by bacterial or viral infections, and are characterized by exudative inflammatory changes in the lungs, usually confined to one segment or lobe. Most of the two pneumonic foci, which may be accompanied by clinical symptoms such as cough, sputum, fever, chest tightness, shortness of breath, and chest pain, are associated with viral, bacterial, or mycoplasma infections. Diseases such as bronchitis or pneumonia are usually considered, and the diagnosis can be clarified by combining the patient’s clinical manifestations, imaging and laboratory tests. Patients with two pneumonic foci are recommended to do further examination under the guidance of specialized physicians, and take appropriate treatment measures after clear diagnosis.