The Third Edition of Symmetry and Structure builds on the foundation of the second edition and turns the complex and potentially difficult subject of group theory into an accessible and readable account of this core area of chemistry. By using a diagrammatical approach and demonstrating the physical principles involved in understanding group theory, Symmetry and Structure provides a non-mathematical, yet thorough, treatment of this broad topic. The past decade has seen a significant decline in the mathematical awareness of chemistry students.  The Third Edition of Symmetry and Structure addresses this in two ways.  Firstly, the mathematical appendix will be re-written at a more accessible level and secondly, character tables will be represented pictorially.  The application of group theory to chemistry hinges on the use of so-called irreducible representations.  These appear as sets of numbers, either on their own or in compilations character tables.  The mathematics of the subject, in large measure, deals with the properties of these sets.  It is impossible to cover the subject without irreducible representations or character tables they are a key part of the subject.  The third edition will introduce this aspect of the subject in a pictorial way and has enabled a further simplification of the presentation of the subject matter.   This new edition has been fully revised and updated to include a much more three-dimensional and accurate visualization of many of the key topics (for example, orbitals).  The chapter on octahedral molecules will be extended to cover the important topic of the ligand field theory of octahedral transition metal complexes.