The purpose of this book is to provide a comprehensive source of information regarding NSAIDs in detail. NSAIDs are widely used and prescribed to all age groups. This book represents a new approach for undergraduate and post-graduate medical students of all specialties. The book was written in simple and easily understandable language for everyone. This book is mainly focused on NSAIDs and related topics like mechanism and pharmacological actions, adverse drug reactions, fixed dose combinations, poisoning of overdose, usage in neurological conditions, geriatrics, paediatrics and pregnancy, NSAID-induced gastropathy and nephropathy, NSAIDs in oncology, pharmacogenomics, and in COVID. Their use is associated with a vast spectrum of adverse drug effects, so drug selection is crucial in various conditions. Each chapter of the book presents the pharmacology of NSAIDs in the framework of biochemical, physiologic or pathophysiological systems. Each topic provides an understanding of the basic concepts of NSAIDs on already existing and on newer drugs and their pharmacological use in various organ systems at different age groups. Updated and recent information including the use of NSAIDs in COVID has been added. Detailed drug information in aspects of drug selection and its contraindications as per patients' disease status and updated approaches in newer clinical perspectives were included. Diagrams, tables, and flowcharts are included to make the concepts easier to understand. At the end of each chapter, useful references are added for further reading.