Inflammation is the local response of a complex organism to an injury that serves as a mechanism initiating the elimination of noxious agents and of damaged tissues. Free radicals, and the very special free radical nitric oxide, are playing a relevant role in the pathogenesis of inflammation. This work introduces the general knowledge necessary to understand the inflammatory process and the role played by free radical and oxidative stress. The interplay between inflammatory molecules and cell signalling is also dealt with in depth. A second part is dedicated to nitric oxide, redox regulation and antioxidant function in inflammation. The final chapters are devoted to diseases where inflammation plays a dominant role - septic shock, end-stage renal disease, neurodegenerative, ischemic and lung diseases.