Based on the author's long teaching experience, this book has been developed from lecture scripts of courses held in the USA and in Germany. It comprises the molecular orbital model to explain covalent bonding in organic molecules, the classes of organic compounds including natural products, polymers and biopolymers, basic concepts (orbital hybridization, resonance, aromaticity), types and mechanisms of organic reactions, and essential aspects of molecular structure such as atom connectivities, skeletal isomerism, conformation, configuration and chirality. Each of the short chapters presents important knowledge at a glance and includes several questions and answers for self-examination. A compact and concise textbook for chemistry students which is perfect for exam training (MS and BC).