X-ray crystallography has been a vital method for studying the structure of proteins and other macromolecules for many years. As the importance of proteins continues to grow in a wide range of research fields, more and more researchers have found a knowledge of X-ray diffraction to be an indispensable tool. Professor Drenth, recognized internationally for his numerous contributions to crystallographic research, has provided a technically rigorous introduction to the subject. This book provides the theoretical background necessary to understand how the structure of proteins is determined at atomic resolution. It is intended to be an introduction for graduate students, postdoctoral researchers, and established scientists who want to apply protein crystallography in their own endeavors, or need to understand the subject in order to critically evaluate the literature. Principles of Protein X-Ray Crystallography is appropriate as a textbook for courses in biochemistry and biophysics, including protein structure and function, structural biology, and macromolecular structure.