This book provides an overview of all aspects of therapeutically relevant aspirin actions and the underlying modes of action. Pharmacologically, focus is on the unique structural properties of the compound consisting of two bioactive molecules, i.e. a reactive acetyl group coupled to the salicylate moiety with unique physicochemial properties as well as the primary metabolite salicylic acid itself. Both exhibit different pharmacokinetic and pharmacodynamic properties that synergize in many cases. Subsequent to an introductory section on the fascinating history of the detection of aspirin, and important early findings, the pharmacology, toxicology and clinics of aspirin are discussed in three main chapters, each divided into several subsections. A list of references is found in each section and includes a selection of papers that have been published by the end of 2020. Subsequent to two English, three German and one Chinese editions, this is the third edition in English.