Michel Daudon is a worldwide recognized biologist who performed several major breakthroughs in the field of urolithiasis. It is indeed difficult to address his outstanding personality and his great contributions to urolithiasis. Michel Daudon studied many aspects of urolithiasis, from urine crystals to kidney stone morphoconstitutional analysis. He is the author of more than 500 scientific articles on urolithiasis, and more generally on pathological calcifications, including several books and nice articles in the New England Journal of Medicine, The Lancet, Kidney International, among many others. Michel Daudon is not only a prolific writer; his broad fields of interests range from chemistry to biology or renal pathology, but also clinical bedside subjects explain his success and his attractive way of explaining pathophysiological processes. He has already given more than 300 lectures, in France as abroad.