We analysed the clinical manifestations and echocardiographic findings of cardiac metastases in 18 lung cancer cases treated in our hospital in fifteen years. All cases were chest x-ray and bronchoscopy proved lung cancer patient with cardiac metastases diagnosed by pericardial effusion cytology and echocardiographic examinations. The echocardiographic findings were as follows: 1 case with a large round-like mass constricting heart exteriorly, 2 cases with intracardiac metastases, 2 cases with both effusion and mass within the pericardial space, 13 cases with various amount of pericardial effusion characterized by quick fluid re-accumulation after pericardiocentesis. Finally, we integrate with the documents and probe into the main clinical clues and echocardiographic findings of cardiac involvements in lung cancer patients with cardiac metastases. We warn the clinical practitioners that if the diagnosed lung cancer or other malignant tumor patients exibit cardiac arrhythmia, heart failure, enlargement of heart or development of new heart murmur etc. with unknown causes in clinical practice, the possibility of cardiac metastases should be suspected and echocardiography should be done to help diagnose the sites of cardiac involvements and the degree of severity.