Pericardiocentesis with catheter insertion and drainage is widely used in management of large pericardial effusions and cardiac tamponade. Two potential problems with an indwelling pericardial catheter system are catheter blockage and infection. We have utilized slow infusion of heparinized saline solution (3 ml/hr) via a continuous flush device to maintain catheter patency for up to seven days (mean 3.6) in 16 patients. Pericardial effusions were secondary to malignancy, uremia, and cardiac surgery. This article describes practical aspects of the technique. Most pericardial effusions can be successfully treated with pericardiocentesis and catheter drainage, provided the drainage is continued reliably and safely for several days. Surgical treatment such as subxiphoid pericardiostomy or partial pericardiectomy should be reserved for loculated effusions, clotted blood, subacute effusive-constrictive pericarditis, or significant recurrences after initial drainage.