Negative pressure wound therapy (NPWT) has transformed modern wound care by leveraging controlled suction to improve healing. This chapter explores the mechanisms of NPWT, including microdeformation, macrodeformation, moisture balance and fluid management, and variations in blood flow, each contributing to cellular and tissue changes that improve wound healing. Additionally, we examine application structure and kinetics, including pore size, suction intensity and frequency, and wound stiffness, which impact NPWT’s effectiveness. Together, these structures impact tissue responses, influencing peripheral nerve regeneration, mast cell activation, angiogenesis, and lymphatic function. Innovations such as NPWT with instillation and dwell time therapy (NPWTi-d), which combines NPWT with fluid instillation, and closed-incisional NPWT (ci-NPW), designed for closed incisional management, have expanded NPWT’s clinical utility. Looking ahead, the future of NPWT lies in personalized, AI-driven therapies, bioengineered dressings, and drug-delivery systems that optimize healing at a cellular level. Smart NPWT devices with real-time monitoring and advanced biomaterials will continue to redefine wound care. As research advances, NPWT will evolve from a mechanical therapy to an intelligent, adaptive healing platform, offering tailored solutions for complex and chronic wounds worldwide.