The book "Targeting Protein-Protein Interactions by Small Molecules" provides a comprehensive analysis of the latest strategies for developing inhibitors for protein-protein interactions (PPI). It is divided into two parts and includes a total of twelve chapters that cover both design strategies and case studies on small molecules as PPI inhibitors. The first part of the book focuses on various discovery strategies, including high-throughput screening, hotspot-based designs, computational approaches, and fragment-based designs. The second part highlights recent advances in small molecule inhibitors, particularly clinical candidates and new PPI targets. This specialized book is aimed at professionals in pharmaceutical science and medicinal chemistry, offering valuable insights into the development of new drugs.