In this work 45 living related kidney donors (LRD) and 20 healthy sex and age matched controls were examined. Donors were evaluated up to 122 months after donation. Hyperfiltration was observed in the remaining kidney with a mean one-kidney GFR value of 82.9 +/- 36.8 ml/min while the control value was 71.04 +/- 31.5 ml/min. The kidney was significantly larger in the donor group than in the controls. In the LRD group, 3 were hypertensive, 7 showed microscopic haematuria and 5 had mild proteinuria. In the control group 3 were mildly hypertensive, and 2 showed microscopic haematuria. Serum creatinine of the donor group was found to be significantly higher than in the controls, yet it was stable and within the normal range (0.89 +/- 0.28 mg/dl). Examination for microalbuminuria showed that 11% of the donor group excreted higher amounts of albumin, being above the upper limit of the control group. We have concluded that kidney donation will result in minor abnormalities in kidney functions which will not affect the donor morbidity or mortality.