In this prospective, randomized, single-center study, with regard to the high cost of monoclonal antibodies (MAb), we intentionally show the efficacy and safety of only one dose induction of Daclizumab (DZB) [Zenapax, Hoffman LaRoche, humanized anti-interleukin-2 receptor (IL-2R) MAb] among adult recipients of live unrelated donor renal graft. Eligible patients got induction with only one dose of DZB (1 mg/kg), intentionally just the day before renal transplantation surgery. This group was compared with those patients who did not get induction with any MAb. The primary outcome measure was the incidence of acute rejection. Secondary outcomes included: cost, changes in serum creatinine level (SCr), primary non function (PNF), and delayed graft function. One hundred patients among 141 renal transplant recipients were selected and they completed the 6-month follow-up. Cyclosporine micro emulsion (CsA), prednisolone, azathioprine, mycophenolate mophetile (MMF), were the drugs used by all of these patients. Mean SCr level at time of discharge was originally lower in the limited-dose DZB group than the rest of population study group who did not received DZB, (0.75mg/dl vs. 1.27mg/dl, respectively). By 1, 2, 6, months, mean SCr values were nearly equal in both group. The incidence of acute rejection was also lower in limited-dose DZB group (22.5% vs. 40%) (P value 0.005). The incidence of delayed graft function was surprisingly lower in limited-dose DZB group in comparison with other group who did not received DZB (7.6% vs. 12.2%, respectively). The cost difference between the standard dose of DZB (1mg/kg, 5 dose, before and after renal transplantation), and limited-dose of DZB was strikingly high (approximately, 2500 us $ vs. 1000 us$, respectively). Primary non function (PNF) occurred only in one patient in DZB group (2.5%), but in control group PNF occurred in 3 patients (5%). One case of Kaposi's sarcoma confined to skin had been detected in DZB group during the first 6 months post transplantation. This study suggests that a limited-dose DZB regimen may be efficacious and less costly alternatives to the standard-dose of DZB for antibody induction therapy for renal transplantation to prevent acute rejection.