Résumé : In our experience the use of OKT3 as prophylaxis in renal transplantation has been associated with an increased incidence of both delayed graft function and thromboses of graft vessels. OKT3 nephrotoxicity might have been favored by restriction of perioperative fluid infusion to prevent pulmonary edema and by the use of very high dose (30 mg/kg) of methylprednisolone (mPDS) before the first OKT3 injection to reduce the release of cytokines. This led us to modify our perioperative management in three ways: (1) hydration status was optimalized; (2) the calcium-channel blocker diltiazem, considered beneficial for recovery of graft function, was administered on the day of transplantation; and (3) the dose of mPDS given before the first OKT3 injection was fixed at 8 mg/kg. Comparison of two consecutive series of patients (group 1, control patients, N = 172; group 2, managed as described above, N = 173) showed that: (1) the incidence of delayed graft function fell from 52% in group 1 to 22% in group 2 (P < 0.0001): (2) the incidence of pulmonary edema was not significantly increased in group 2 (3.5% vs. 1.7% in group 1, P = 0.5); and (3) the frequency of intragraft thrombosis fell from 7.6% in group 1 to 1.2% in group 2 (P = 0.0034). Multivariate analysis showed that the volemia/diltiazem program and avoidance of high mPDS dose were the most important factors responsible for the reduced occurrence of delayed graft function and graft vessels thrombosis, respectively. We conclude that a combined strategy of appropriate dosage of steroids before the first OKT3 injection, administration of a calcium-channel blocker and optimalization of volemia is safe and efficiently prevents against OKT3 nephrotoxic effects.