Modern hemodialysis requires repeated reliable access to blood vessels capable of providing rapid extracorporeal blood flow. This necessity for reliable access to the circulation is the Achilles9 heel of modern hemodialysis. Native and synthetic arteriovenous fistulas remain the preferred method of maintaining long-term hemodialysis access. Vascular access dysfunctions (thrombosis and infection) are the most common complications encountered in the care of end-stage renal disease patients. This article focuses on the mechanisms by which permanent vascular access for hemodialysis is obtained and deals with the common complications that result. This review will evaluate these common complications and outline new methods for improving vascular access patency. New concepts focusing on the prospective detection and correction of venous stenoses as well as on the prevention of other factors that predispose to access failure are explored.