The present book contains the Proceedings of a two day Symposium on Uremic Toxins organized at the University of Ghent in Belgium. A series of guest lectures, free communications and posters have been presented. An international audience of 163 scientists from 16 nationalities listened to and discussed extensively a spectrum of topics brought forward by colleagues and researchers who worked for many years in the field of Uremic Toxins. There is a striking contrast between all the new dialysis strategies available in the work to "clean" the uremic patients and the almost non-progression of our knowledge on uremic toxins in the past decade. In this sense the symposium was felt by all participants as a new start for the research in the biochemical field of the definition of uremia. If the present volume would stimulate new work in this field in order to define uremia, or identify the uremic toxins, the purpose of the organizers would be maximally fulfilled.