Blood pressure (BP) elevation and left ventricular hypertrophy are important factors in the high cardiovascular mortality rate in patients on the renal replacement program. Ambulatory BP monitoring is widely regarded as superior to random BP monitoring in predicting end-organ damage from elevated BP. One hundred seventeen patients (60 on hemodialysis [35 with long sessions and 25 with short sessions], 29 on continuous ambulatory peritoneal dialysis, and 28 transplant recipients) underwent ambulatory BP monitoring, with target organ assessment by electrocardiography. Mean 24-hour BP for the patients with the long hemodialysis sessions (LHD) was 115.5/66.6 mm Hg, without the regular use of antihypertensive drugs. The parathormone (PTH) level was the major determinant of BP on ambulatory BP monitoring analysis, with interdialytic weight gain and age each having weaker associations. The BPs of the other three patient cohorts were much higher (short hemodialysis session [SHD], 143.2/82.1 mm Hg; continuous ambulatory peritoneal dialysis, 137.1/76.8 mm Hg; transplant recipients, 135.9/79.2 mm Hg). Overall, two thirds of the patients had reduced diurnal BP variability. Electrocardiogram voltage criteria for left ventricular hypertrophy were exceeded in approximately one third to one half of the patients. Our findings show that good control of BP is possible without recourse to antihypertensive drugs in the context of dialysis with slow ultrafiltration.