Nanotechnology is a perfect blend of science, engineering, and technology conducted on a nano-scale. Few nanomaterials can occur naturally, however, in recent times, we are interested in engineered nanomaterials which can be manufactured according to their applicability in a lot of commercial products and processes. For the synthesis of new nanomaterials, scientists mostly opt the bottom-up methods which are capable of offering various kinds of self-assembly of nanoscale species. Parallelly, topdown methods are also being investigated to yield desired nanomaterials and nanopatterns through state-of-art modern techniques like lithographic ablation and chemical etching. In this chapter, after providing an introduction to nanotechnology and nanomaterials, the various methods of nanomaterial synthesis were discussed. Nanotechnology is now being explored vastly to reach the next generation phase of many technologies and industrial sectors. Contributions of nanomaterials to some of such emerging technologies, like the food industry, agricultural science, medicinal science, and the power sector have been briefly overviewed. The rapidly developing sectors involving ultrafine nanoparticles introduced mankind to their hazardous side too. To avoid nanotoxicity, the awareness and related risk management approach are also a matter of utmost importance.