The incidence of treated end-stage renal disease (ESRD) in the United States is four times more frequent in African-Americans (AAs) than in whites. This is explained neither by a greater prevalence of hypertension and diabetes mellitus nor by socioeconomic issues. To investigate familial risk of renal disease in AAS, we examined the records of 472 AA dialysis patients in Jefferson County, Alabama. Applying strict criteria, we identified 85 Index cases of ESRD associated only with hypertension (H-ESRD). We examined the records of 75 index cases and studied the first-degree relatives of 40 patients. The numbers of men and women with H-ESRD were similar (38 and 37, respectively). There was no statistical difference in age at the onset of dialysis (women 53.7 ± 13.5 years [±SD] and men 49.2 ± 12.2 years; P = 0.0863). We found evidence for renal disease in 26 of 40 (65%) index cases with participating families. Hypertension was present in all 40 families (100%) and diabetes mellitus was present in 24 families (60%). Eighteen of the 75 H-ESRD index patients had a first-degree relative with ESRD. In total, we found evidence for renal disease in 35 of 75 (47%) families. We conclude that there is a strong concordance of renal disease in the families of AAs with H-ESRD.