We performed echocardiography on 19 hemodialysis patients before and after dialysis session. The patients were divided into three groups (normal pressure group; N=9, pre-dialysis hypertension group; N=6, pre-and post-dialysis hypertension group; N=4). The findings of echocardiography (Left ventricular end-diastolic dimension; LVDd, Left ventricular ejection fraction; EF, Left atrial dimension; LAD, Interventricular septal thickness; IVT) were compared in the three groups. There was no significant difference in LVDd and LAD between three groups. The mean value of EF was significantly (P=0.03) higher in the pre-dialysis hypertention group (68±9.4%) than in the normal pressure group (65±9.6%). The mean value of IVT was significantly (P=0.01, 0.01) higher in the pre-dialysis hypertention group (11±0.9 mm), pre-and post-dialysis hypertention group (11±0.6 mm) than in the normal pressure group (10±1.7 mm). These findings suggested thet hypertension may affect cardiac function. Therefore, we concluded that to keep normal blood pressure is important in hemodialysis patients.