Both methods of hypothermic preservation of kidneys currently used clinically have been and continue to be useful procedures for the transplant surgeon. Each method has its limitations, benefits, and potential detriments. Which method is best is not a fully resolved question and the method of choice appears to be dependent upon, to a large extent, personal preference and circumstances. There is, however, a vital need for long-term kidney preservation. Obtaining this goal will most likely require carefully controlled experimental studies linking the biochemical and physiological aspects of organ metabolism at hypothermia to the design of perfusates, perfusion machine technology, and drug therapy. Improvements in perfusion preservation methodology based on sound basic data rather than by serendipity appears to offer the best opportunity for obtaining good quality long-term preservation.