The changes in left ventricular anatomy in 30 patients with end-stage renal disease and stable cardiac function, undergoing regular haemodialysis (10 patients), continuous ambulatory peritoneal dialysis (10 patients) and after successful renal transplantation (10 patients) were evaluated by M-mode echocardiography. Initially all had evidence of left ventricular hypertrophy and dilatation. Reevaluation after a mean follow-up of 22 months on each mode of treatment showed that in the haemodialysis group the left ventricular mass and volume were increased, while in continuous ambulatory peritoneal dialysis (CAPD) and, especially renal transplantation, the hypertrophy and dilatation were reversed. This improvement was probably due to a reduction of cardiac workload.