This chapter describes the use of common salt with varying amounts of nitrates and nitrites used for curing and preservation of meat. Preservation of meat is done by smoking and cooking. The chapter gives a brief explanation on the chemistry of curing process, botulism that is one of the most serious forms of food poisoning, and the toxicity of nitrates. Chemistry of nitrosamines consists of nitrosation and rate of reaction, general synthetic routes to N–nitrosamines, the properties and structure, and chemical reaction. Biological properties of nitroso compounds are carcinogenicity, consists of epidemiological and animal studies and biochemical changes, effects the human organs. It also describes the analytical aspects of nitrosamines and its presence in biological materials, foods, and tobacco. The chapter concludes by specifying the concern over the presence and formation of nitroso compounds in foods and in other areas of the environment that will undoubtedly continue for several years ahead and further progress of principal analytical task of devising methods capable of detecting, identifying, and measuring nitroso compounds.