The aim of this book is to provide an introduction to all those who wish to use the complementary spectroscopic techniques of optical activity (circular dichroism, CD) and optical anisotropy (linear dichroism, LD) for the study of the structure of molecules and interactions between moleculesin solution. The emphasis of the book is on what the techniques are and how to use them for both low and high molecular weight molecules. It is intended to be an easy guide to what a prospective user of CD needs to know and explains how LD is not merely an exotic technique only to be practised byexperienced spectroscopists, but may be routinely and usefully employed as an aid to molecular structure determination. This book begins by describing the principles behind CD and LD and how these techniques can be used in the laboratory without using advanced maths or quantum mechanics. The next chapters describe how both techniques may be applied to the study of biological macromolecules and give a detaileddescription of how they may be used on small molecules to investigate molecular and electronic structure. The final part contains theoretical derivations of all the equations required for the applications described previously. Throughout the book specific molecular examples are used to illustrateconcepts and to show the reader how to use the techniques in chemical and biological systems. Circular Dichroism and Linear Dichroism is the first book that is an easy, directly applicable manual to the use and interpretation of both CD and LD. It will be of use to both novices and experiencedresearchers in the field.