A new double-lumen silicone-rubber dialysis catheter, designed to be placed surgically in central veins, is now available. There is little published data concerning the long-term use of this catheter for hemodialysis, but a review of the literature suggests that pericatheter thrombus formation with or without occlusion of major veins has been a complication of chronic central venous catheterization with a variety of catheters, in both dialysis and nondialysis settings. We had this catheter placed in four diabetic patients who had severe problems related to maintenance of adequate vascular access. Two of the four patients underwent venography within 3 months of catheter placement because of impaired catheter function and were found to have thrombi on the outside of their catheters. These thrombi could not be dissolved with fibrinolytic agents, and the catheters were removed surgically without incident. The other two patients have no radiologic evidence of thrombus formation 4 and 7 months, respectively, after catheter placement. We suggest that proper selection of patients for this type of vascular access should be the subject of future studies and that patients with malfunctioning catheters undergo venography to rule out the presence of significant catheter related thrombosis.