BP obtained in the dialysis unit by technicians and nurses without attention to detail differ strikingly from BP obtained using standard methods. Nearly half the systolic BP are more than 10 mm Hg different from routine BP when standard methods of measurements are used. BP obtained before and after dialysis, even if obtained using standardized methods, agree poorly with interdialytic ambulatory BP. Furthermore, even standardized BP recordings cannot be used to predict the presence or absence of left ventricular hypertrophy.