Carbon fiber reinforced plastic materials play a major role in the applications of aeronautic, aerospace, sporting and transportation industries. Mechanical drilling is unavoidable and it is important final machining process for components made of composite material. Delamination is one of the major defects to be dealt with. This review paper showcases the importance of an adequate selection of drilling tools and machining parameters to extend the life cycle of these laminates as a consequence of enhanced reliability. Before we analyze the cause and effects of delamination we need to understand the behavior of different composite materials towards mechanical drilling. Such detailed aspects of drilling on various composite materials will benefit from a comprehensive literature review on drilling of composite materials. This review paper summarizes the characters exhibited by different composite materials over drilling.