Living kidney donor evaluations and follow-up have previously been addressed mostly by transplant physicians and surgeons. However, this area is significantly informed by basic principles of renal physiology and is of increasing clinical interest to general nephrologists. The general nephrology community is increasingly involved in evaluating the suitability of potential donors and in following them after donation when questions are raised about low GFR, hypertension, and other renal concerns. This article focuses on some of the most central and common issues that arise in evaluating potential donors and attempts to provide guidance on the basis of our review of the living donor literature, extrapolations from the general nephrology literature, and our own clinical experience.