Background.The aim of this study was to compare the effectiveness of intravenous immunoglobulin (IVIg) versus monoclonal anti-CD3 as a treatment for steroid-resistant rejections. From January 1995 to June 1997, 30 patients were analyzed. They were randomized into two groups. Resistant rejections were diagnosed by core biopsy. Group A received 500 mg/kg/day IVIg (Sandoglobulin) for 7 consecutive days, whereas group B received 5 mg/day of OKT3 for 14 consecutive days. Daily T cell CD3+peripheral count was performed for 14 days for group B. The immunosuppression was similar for both groups. Cyclosporine was stopped during both treatments.Methods.Demographic factors, HLA mismatch, creatinine levels before and after treatment, and the incidence of rejections after treatment (up to 1 month) were taken into account for this study.Results.Data from different samples were compared using Fisher’s exact test. Graft and patient survival were analyzed using the Kaplan-Meier method. The were no significant differences found in age, graft origin, HLA mismatch, or time of follow-up until the episode of rejection. Success was achieved for 11 (73.3%) of 15 of group A and 13 (86.6%) of 15 of group B (P=0.79). Creatinine levels before and after treatment were as follows: A, 2.99±1.30 mg/dl and 2.1±0.70 mg/dl versus B, 3.1±1.1 mg/dl and 2.5±0.8 mg/dl. Besides, we did not observe differences in the creatinine 1 month after treatment (A: 2.35±0.78 mg/dl; B: 2.51±1.10 mg/dl;P=0.66) nor in the third month (A: 1.83±0.58 mg/dl; B: 2.30±0.89 mg/dl;P=0.24). The incidence of rejections after treatment was 5 (46%) of 11 for group A and 9 (75%) of 12 for group B (P=0.4). The patient survival rates 2 years after treatment were 87 and 92% for A and B groups, respectively. Graft survival was identical (80% in both groups).Conclusion.Should the favorable result presented in this report be confirmed in larger number of patients, IVIg could become the preferable choice of rejection treatment for steroid-resistant rejection because of a complete absence of the unwanted side effects commonly associated with OKT3.