This chapter is devoted to describe self-healing materials, with special reference to biobased polyurethane and its nanocomposites as materials for today’s civilized society. It covers the concept, importance, basic understanding, and classification of such a novel class of materials. Various approaches to obtain self-healing materials and their mechanisms are elaborated in this chapter. Applications of such materials with respect to the current scenario of materials are also briefly present here. Concluding remarks and suggestions for future work in the field are presented at the end of the chapter.