Book excerpt: Nowadays, the use of composite materials has increased in various areas of science and technology due to their special properties, namely for these application in aircraft, automotive, defence and aerospace industries as well others advanced industries. Drilling is a frequently practised machining process in modern industry owing to the need for component assembly in composite structures. This book aims to provide the research and review studies in drilling of composite materials. The first three chapters provide information on delamination and damage reduction in drilling of composite materials. The following two chapters deal with influence of machining parameters on the delamination. The sixth chapter is focused on modelling of drilling aluminium matrix composites using artificial neural networks. The chapter seventh is dedicated study of analysis of delamination in drilling wood composite medium density fibreboards. Finally, the last chapter of this book is focused on studies on composite drilling - the state of the art. The present research book can be used as for final undergraduate engineering course (for example, mechanical, manufacturing, materials etc) or as a subject on machining/composites at the postgraduate level. Also, this research book can serve as a useful reference for academics, manufacturing and materials researchers, manufacturing, materials and mechanical engineers, professional in composites technology and related industries.