Summary Small blood pressure (BP) elevations may occur post kidney donation. This prospective study determined 24-h ambulatory BP (ABP) and other cardiovascular risk factor changes in 51 living donors over 12 months postdonation. Donors also provided 24-h urine collections for monitoring protein and creatinine clearance, 75 g oral glucose tolerance tests (OGTT), and fasting lipids. Nondipping was defined as night-day systolic (SBP) ratio >or=0.9. Baseline and 12-month pre to postdonation comparisons were made both for dippers and nondippers. Of 51 donors, 35 were dippers and 16 nondippers. In these two groups, predonation 24-h SBP were 115.2 +/- 8 and 115.6 +/- 10 mmHg; serum creatinine (SCr) 69.3 +/- 12 and 71.1 +/- 13 micromol/l; and 24-h urine protein 0.12 +/- 0.05 and 0.09 +/- 0.03 g (all P = NS) while at 12 months, 24-h SBP were 111.4 +/- 11 and 114.3 +/- 8 mmHg (P = 0.384), SCr 97.9 +/- 16 and 97.7 +/- 21 micromol/l (P = 0.810); and 24-h urine protein 0.139 +/- 0.09 and 0.111 +/- 0.07 g/d (P = 0.360) respectively. The 24-h SBP was significantly lower in the dippers at 12 months as compared with predonation (P = 0.036). OGTT and lipid profiles remained normal in both groups. Predonation nocturnal nondipping does not carry adverse postdonation consequences over 12 months.