The book is intended to serve as a primer to combustion. It has been the author's experience that too many scientists with interests in com bustion phenomena have very limited knowledge of the field as a whole. For example, many chemists who have acquired a deep understanding of the mechanism of branching-chain reactions in closed vessels are completely uninformed about the importance of such processes in flames or detonation waves. This is a severe limitation because the essential feature of all combustion phenomena is that they arise as a result of the interplay of physical and chemical processes and a complete understanding can result only if aspects of mechanical engineering and fluid mechanics are taken into account. The aim of this text is to provide the basic principles which form the background to all combustion phenomena. It is based on a course given to postgraduate students in chemistry at the University of Essex and it is the author's hope that it can be read by final-year undergraduates and research personnel in a wide range of disciplines. The major problem for the author has been that of selection. Because the book is intended to be short, many topics of interest have been omitted and, since decisions as to content have been entirely arbitrary, many readers will disagree with the choice. The author has tried to adhere to certain principles in making the selection.