Hemodialysis is a technically sophisticated therapy used to remove accumulated uremia toxins and correct the electrolyte, hydrogen ion, and fluid imbalances associated with renal failure. Hemodialysis is indicated when the morbidity or potential mortality from either acute or chronic renal failure cannot be alleviated by conventional therapies. Additionally, it is useful for the rapid removal of excessive fluid loads associated with congestive heart failure or iatrogenic fluid administration and the elimination of dialyzable poisons like ethylene glycol. The requirements for hemodialysis include repeated access to the vasculature, an artificial kidney, and a dialysis delivery system. Technologic advancements in all these requirements make the delivery of hemodialysis feasible, effective, and safe for both dogs and cats. To date, the limitation of facilities offering dialytic therapy has restricted its use in uremic animals but current improvements in dialysis techniques and the increased sophistication of specialty practice make hemodialysis a realistic adjunct to the conservative management of uremia in veterinary medicine.