To describe recovery of renal function (RC) in Black South African patients with primary malignant hypertension (MHT) and end-stage renal failure, according to the type of dialysis provided. A retrospective analysis of the records of 31 patients with MHT. A university-based, large tertiary-care hospital and its community-based satellite continuous ambulatory peritoneal dialysis (CAPD) clinics. Only patients with renal failure caused by MHT and who were on dialysis between January 1997 and June 2000. There were 11 patients on peritoneal dialysis (PD) that regained renal function; 11 patients on hemodialysis (HD), none of whom recovered renal function; and 9 patients on PD who did not recover renal function during the same time period. The groups were investigated for variables that might predict RC. Peritoneal dialysis compared with HD was highly significant as an indicator of RC (p < 0.0001), with 60% of patients on PD regaining renal function, versus 0% on HD. Median time to recovery was 300 (150 -365) days. There was no significant difference in decline of mean arterial pressure (MAP) between the groups; MAP declined significantly in all groups (p = 0.00002). All groups received similar drug therapy. In the RC group, initial MAP, kidney size, and urine output tended to be higher and creatinine lower (p = not significant). Dialysis adequacy was similar in the different groups. This retrospective study suggests there may be benefit from PD as the primary form of dialysis when patients have MHT as a cause of their renal failure. Possible predictors of RC include blood pressure control, initial MAP, initial serum creatinine, initial urine output, and kidney size. Time should be allowed for RC before transplantation is undertaken. Prospective studies are needed to confirm the benefit of CAPD in patients with MHT.