The textbook "Elements of Medical Biophysics" deals with phenomena discussed at biophysics seminars for the students attending MD and DDS courses. The textbook has been written by the teachers of the Department of Biophysics at University of Medical Sciences in Poznań. For the very first time, the issues discussed at the seminars have been collected to enhance the students` capability for preparation for classes and further study. The aim of the textbook is to provide and systematize knowledge about selected physical phenomena, their influence on the human organism and application in diagnosis and therapy. In order to use "Elements of Medical Biophysics" effectively one ought to be familiar with the basic issues brought up at the laboratory classes and lectures. The first three chapters deal with the influence of electromagnetic radiation on living organisms. The chapters are an introduction to chapters V and VI on computed X-ray tomography, SPECT and PET tomography, and NMR tomography. In these chapters the reader gets acquainted with physical basis of the discussed imaging method. Chapter IV describes the issue of radiotherapy and introduces its physical and radiobiological aspects. Chapter VII focuses on the physical basis of one of the most commonly used imaging method which is ultrasonography. Chapter VIII provides a general introduction to analysis of bioelectric processes presented on an ECG curve. Each of the chapters provides bibliography which enables the students to extend their knowledge of the subject. The present textbook is a continuation of the experience and work of my colleagues from the Department of Biophysics. I am especially indebted to the Head of the Department Professor Feliks Jaroszyk for his kind support. I wish to thank my colleagues for their assistance and cooperation in writing "Elements of Medical Biophysics". I will find any comments and suggestions the users may have extremely helpful in preparing next issue of the textbook. Leszek Kubisz