This book is envisioned to cover the fundamentals of medicinal chemistry. The third edition of this book is useful to seasonal medicinal chemists as well as to chemists entering academic or industrial laboratories. It provides a hands-on overview of the drug discovery process. This edition differs from the previous two editions by having been updated to reflect developments in the past 10 years. This volume encompasses 20 chapters. Chapters 1 to 7 discuss various fundamentals of medicinal chemistry, including receptors, physicochemical properties of drug molecule, prodrug concept. Each chapter includes a brief introduction, chemical classification with examples, trade name, structure with IUPAC name, synthesis for selected drug molecules, mechanism of action and uses, and metabolism, etc. This volume covers the drugs acting on ANS, CNS, NSAID, cholinergic, adrenergic and including prostaglandins at the end.