From June 1987 to January 1991, 24 patients with moderate or massive pericardial effusion underwent subxiphoid pericardial window procedures for diagnosis and therapy. The patients` ages were ranged from 28 years to 71 years. The underlying diseases were chronic renal failure with long term hemodialysis in 3 cases, malignant lung cancer in 7 cases, stomach cancer in 2 cases, tuberculous pericarditis in 5 cases, pyogenic pericarditis in 2 cases, myxedema in one case, one metastatic squamous cell carcinoma from unknown origin and three of undefined etiology. Preoperative diagnoses of pericardial effusions were confirmed by echocardiogram in all cases. Subxiphoid pericardial drainages were performed under general[n=19] or local anesthesia[n=5]. Histological diagnoses were made from the inferior pericardial tissue in all cases except one. In this one case[tuberculous pericarditis], the subxiphoid pericardial approach was failed from intraoperative bleeding. There were two postoperative death, one[in malignant lung cancer] had postoperative ventricular tachycardia which result in cardiac arrest, and the other[unknown origin metastatic malignant effusion] had persistent tachyarrhythmia postoperatively and died on postoperative 5th days. Twenty three patients were followed up from 3 days to 9 months; mean follow-up day was 43 days. The preoperative and postoperative mean cardiothoracic ratio in chest x-ray were 0.69 and 0.52 respectively. Subxiphoid pericardial drainage may provide definitive diagnosis and treatment for pericardial effusions. The approach through subxiphoid pericardium under general or local anesthesia avoids the complications of pericardiocentesis and is effective for malignant pericardial effusion.