Infectious complications of hemodialysis include bacterial infections caused by contaminated water or equipment, other bacterial infections (including vascular access infections), and bloodborne viruses (primarily the hepatitis B and C viruses). Infections caused by contaminated water and equipment can be prevented by a well-designed water-treatment system, routine cleaning and disinfection of system components, and routine bacteriologic monitoring of dialysis water and dialysis fluid. Standard precautions with additional measures recommended specifically for dialysis centers will prevent transmission of bacteria and viruses from patient to patient. These precautions include routine use of gloves, handwashing, and cleaning and disinfection of the external surface of the dialysis machine and other environmental surfaces. In addition, preventing transmission of hepatitis B virus infection requires vaccination of susceptible patients and staff, avoiding dialyzer reuse, and use of a dedicated room, dialysis machine, and staff members when treating patients chronically infected with this virus.