Twenty-nine patients with acute renal failure following bites by snakes of the genera Crotalus and Bothrops were treated in an Intensive Care Unit (ICU). Eight were given conservative treatment. Peritoneal dialysis was necessary in 21 patients, and hemodialysis in one of these. The main complications occurring while the patients were in the ICU were pulmonary edema (5 cases), respiratory failure (4), cardiac arrest (4), and hypovolemic shock (1 case). Three patients died with respiratory and hemodynamic disturbances while in the ICU, one of them during the polyuric phase. Twenty-four patients were discharged from the hospital with no clinical or laboratory evidence of renal failure. Two patients developed bilateral cortical necrosis of the kidney. One of them died in the general ward after interruption of dialysis and the other was discharged from the hospital with chronic renal failure. It was not possible to perform a kidney transplantation. The importance of the ICU in the recovery of such patients is stressed.