In the last three decades the ever growing volume and ever changing nature of our understanding about reaction mechanisms are witnessed. Authors aims to describe the fundamental principles of organic chemistry with an emphasis on the characteristic reactions of various functional groups. The text is divided into two parts. The first five chapters are devoted to the basic principles and concepts underlying chemical reactions while in rest of the chapters, stress is given on structures and reactions of organic compounds. However, the wide scope of the subject has necessitated restrictions to keep the size of the book within reasonable limits. This book is also useful for the students of Rajiv Gandhi University, Karnataka.