The primary objective of this 4-volume book series is to educate PharmD students on the subject of medicinal chemistry. The book set serves as a reference guide to pharmacists on aspects of chemical basis of drug action. This first volume of the series is comprised of 8 chapters focusing on basic background information about medicinal chemistry. It takes a succinct and conceptual approach to introducing important fundamental concepts required for a clear understanding of various facets of pharmacotherapeutic agents, drug metabolism and important biosynthetic pathways that are relevant to drug action. Notable topics covered in this first volume include the scope and importance of medicinal chemistry in pharmacy education, a comprehensive discussion of the organic functional groups present in drugs, and information about four major types of biomolecules (proteins, carbohydrates, lipids, nucleic acids) and key heterocyclic ring systems. The concepts of acid-base chemistry and salt formation, and their applications to the drug action and design follow thereafter. These include concepts of solubility and lipid-water partition coefficient (LWPC), isosterism, stereochemical properties, mechanisms of drug action, drug receptor interactions critical for pharmacological responses of drugs, and much more. Students and teachers will be able to integrate the knowledge presented in the book and apply medicinal chemistry concepts to understand the pharmacodynamics and pharmacokinetics of therapeutic agents in the body.