The effect of hemodialysis on myocardial function in 10 pediatric chronic hemodialysis patients was assessed utilizing echocardiography. Parameters of cardiac function were measured prior to and immediately after dialysis. A significant decrease in cardiac output was observed post-dialysis. Unlike that observed in adult patients a real improvement in myocardial function as indicated by an increase in the mean velocity of circumferential fibre shortening was evident post-dialysis.