Pulmonary metastases are malignant tumors originating from other sites that metastasize to the lung tissue via blood or lymphatic fluid. Lung metastases occur in 20% to 30% of patients with malignant tumors. Primary malignant tumors are mostly from breast, bone, gastrointestinal tract and genitourinary system. The duration of occurrence of lung metastases varies, and a few lung metastases are detected earlier than the primary tumor. There is no effective treatment available. Surgical treatment can be considered for a single metastatic lesion in the lung. Most lung metastases are initially asymptomatic or asymptomatic, with a few cases of cough, bloody sputum, fever and dyspnea, which require ancillary tests to detect and confirm the diagnosis. The current standard of care is resection of multiple pulmonary metastases. In the absence of metastases from other sites, surgical resection can achieve a radical cure. Many tumors are insensitive to chemotherapy and radiation, such as soft tissue sarcoma lung metastases, for which surgery is the most important treatment. The 5-year survival rate after surgery is expected to be more than one-third. For a few cases with only a single metastatic nodule in the lung, or several metastases but all are confined to one lobe or one side of the lung, the primary tumor has been controlled after treatment, there is no local recurrence, no metastatic lesions are found in other parts of the body, and the general condition is good, surgery should be considered. Patients with low number of pulmonary nodules after resection of pulmonary metastases have a long tumor-free survival period. The performance of pulmonary metastases varies among different malignant tumors, and the survival period also differs. The most important prognostic indicator is complete resection of the metastases. Long-term remission and survival can be achieved if the metastases are completely resected, complications are avoided, and as much lung tissue as possible is preserved.