50 This study was designed to test the hypothesis that children who are either on dialysis or have received a transplant will academically perform less optimally than their healthy siblings. To test the hypothesis, pediatric patients either on dialysis or post transplantation (at least 6 months) were recruited from 10 centers geographically distributed so as to obtain a proportionate representation of minority groups. The criteria for inclusion was the availability of a biologic sibling age matched within 3 years. The patient and the sibling control were given standardized tests of achievement which consisted of The Wide Range Achievement Test (WRAT) and the Test of Nonverbal Intelligence (TONI). Results: 48 patients and their controls participated in the study. Of the patients 26 were classified as minority patients (14 African-American, 9 Spanish-speaking [Puerto Rican, Chicano, Mexican-American, Latino], 1 Native American, Asian or Pacific Islander, 1). There was not a significant difference in the age between the minority (Δmean=1.88 years,) and non-minority (Δmean=2.0 years) groups, or between the dialysis(Δmean=1.88), and transplant (Δmean=2.06) groups. Of the minority patients, 46% were younger than their sibling, and of the non-minority patients, 50% were younger. Of dialysis patients, 50% were younger than their siblings, and of transplant patients, 47% were younger. There were no significant differences between minority and non-minority patients for the WRAT standardized scores in spelling, reading, or arithmetic. Transplant patients, however, performed better (p=0.03) in WRAT standardized reading scores (transplant Δmean=2.9) compared to dialysis patients (dialysisΔmean=15.2). Likewise, dialysis/transplant status had a significant combined overall effect on the three differences in WRAT standardized scores(p=0.001). The differences in TONI percentiles between the patient and his/her sibling were not significantly affected by minority status or dialysis transplant status. Conclusion: This controlled study, geographically distributed, failed to confirm the hypothesis that learning achievement is not optimal following dialysis or transplantation but did demonstrate that the achievement performance of children post-transplantation is superior to that of children maintained on dialysis.