End-stage renal disease (ESRD) is strongly associated with both hypertension and diabetes. As both diabetes and hypertension tend to be familial, we hypothesized a familial clustering of ESRD cases. Using 114 cases from three dialysis centers and 99 controls, the exposure odds ratio was determined. Mantel-Haenszel analysis demonstrated that individual history of hypertension (ORmh = 5.14; 95% Cl = 2.29-11.56) and history of chronic renal failure in a first or second degree relative (chi 2mh = 5.12; p less than 0.05) were significant "risk" factors for being dialysed for ESRD, while family history of hypertension posed a more questionable risk (ORmh = 1.92 95% Cl 0.96-3.86). In fact, when the subset of patients identified with hypertensive renal disease was considered independently, the risk due to family history of hypertension increased 14-fold which suggests a role as a confounder for hypertensive renal disease. The effect of chronic renal failure in a relative was independent of family history of diabetes.