Our aim was to estimate the effect of having a functioning cadaveric renal transplant on the risk of cardiovascular and total mortality in patients on renal replacement therapy (RRT). We retrospectively studied (by the Cox proportional hazards regression model) 195 subjects who began RRT with maintenance dialysis in our centre from 1 January 1978 to 31 December 1991. Out of this number, 76 patients received a cadaveric kidney transplant. Cardiovascular abnormalities at the onset of RRT were the principal independent determinant of both total and cardiovascular mortality risk. As compared to patients on dialysis with the same duration of RRT, patients with a functioning renal transplant for more than 1 year had a significantly lower total mortality risk (mean relative risk (RR): 0.48 (0.25-0.91) (95% confidence limits in parentheses), P = 0.03), an effect whose significance disappeared after adjustment for pretreatment conditions (RR = 0.62 (0.30-1.30), P > 0.3). However, the beneficial effect of a functioning renal transplant for more than 1 year on cardiovascular mortality risk was significant, both before (RR = 0.21 (0.06-0.74), P = 0.02) and after the adjustment for pretreatment conditions (RR = 0.32 (0.11-0.90), P = 0.035). During the first year after a successful transplantation the beneficial effect of having a functioning transplant on cardiovascular mortality risk was only weakly attenuated. During RRT a functioning cadaveric renal transplant decreases cardiovascular mortality risk partially independently of the better pretreatment status of the patients selected for transplantation.