In this thesis we have evaluated the long-term impact of living donation by reviewing the recent literature and analysing the current donor eligibility criteria. We have pointed out the limitations of recent studies on long-term outcome after live kidney donation that could have led to a potential overestimation of risk additional to donation. Key problems remain such as that donors are a pre-screened healthy selection of the general population, making it difficult to find an equal healthy unscreened comparison group. Studies should select the entire donor cohort to evaluate long-term outcomes, maintain similar selection criteria for donors and non-donors, match on baseline covariates to enhance comparability, and adjust for follow-up covariates to correct for lifestyle factors. We have evaluated the current donor eligibility acceptance criteria of our own center by performing a comparative follow-up cohort study in which donors were compared to matched non-donors and aforementioned adjustments have been implemented in the study design. The results demonstrated that one year after donation live kidney donors have a reduced renal function, remaining stable without any kidney-related morbidity or mortality to at least eight years of followup. However, the substantial decline in renal function may be further compromised when unforeseen circumstances affect renal function later in life. With the knowledge of this risk, albeit small, donors should be well-informed before donation and be offered lifelong follow-up thereafter. By monitoring the remnant renal function, donors at risk may be identified in early stage and adequate treatment may be offered. We consider this approach a prerequisite to legitimize a living kidney donor program.