In a retrospective study we examined the differences between Caucasian (Group A) and Gypsy (Group B) renal allograft recipients transplanted in Hungary. From 1983 to 2001, 1918 transplants were performed in Budapest (1825 Caucasian and 93 Gypsy recipients). Group B patients were younger (34 +/- 12 vs 42 +/- 14 years of age; P < .01) and Group A had more polycystic kidney disease (12% vs 3%; P < .025). Blood group B was more common in Group B (27% vs 19%; P = NS) than in Group A patients, and Group A had seemingly more diabetes (5% vs 1%; P = NS) than did Group B. There were no differences in HLA mismatches or panel reactive antibodies (PRA). No differences were seen in Group A vs Group B patient survivals at 1, 3, 5, or 10 years' posttransplant (98% vs 95%; 90% vs 93%; 85% vs 88%; and 74% vs 82%, respectively). However, Group A graft survivals were significantly better than Group B at 1, 3, 5, and 10 years' posttransplant (89% vs 77%; 82% vs 66%; 76% vs 54%; and 57% vs 34%; each comparison P < .01). Group B recipients experienced a greater number of acute rejection episodes (66% vs 49%; P < .01), irreversible acute rejections (15% vs 6%; P < .001), chronic rejections (34% vs 18%; P < .001), and graft loss due to immunosuppression noncompliance (5% vs 1%; P < .05) than did Group A recipients. As has been previously described for other non-Caucasian ethnic groups (eg, African-Americans), Hungarian Gypsies appear to be at a greater immunological risk for rejection and poorer long-term graft survival.