Objective To analyze the CT findings of lung cystic echinococcosis with infections, and to assess the value of CT examination. Methods The CT characters of 23 cases of pathologically proved lung cystic echinococcosis were analyzed and CT findings were compared with pathology. Results All 23 cases of lung cystic echinococcosis appeared as single cystic lesions. Fifteen cases appeared in the right lung, and the other 8 in the left. The lesions located in lower lobe were more than those in the upper lobe. According to the CT examination, it could be divided into two types: (1) simple lesion (7 cases) appeared as irregular solid mass with different size, crude edge, and lobulation, and with fiber shadows in the lung field around the lesions. In 6 cases, curvilinear or spotty calcification occurred in the lesions. (2) echinococcosis as a bag (16 cases) appeared as a mass with cystic changes in lung tissue with different size and off-center cystic cavity. The lesions took the form of ball or irregular shape. The edge was crude. Around the focus, prickle-like or patchy changes were detected. Ruptured lesions showed “water snake” or “flow ribbon” signs in 4 cases. In 7 cases, calcification occurred on the cystic wall or extended into the inside contents. Conclusion CT could accurately demonstrate the location, appearance, internal structure, and adjacent situation of the cystic echinococcosis, providing valuable information for correct diagnosis and treatment.