Nitrosamines are a large group of chemical compounds that have been found to be carcinogenic in all species of animals tested. They are classified as suspect human carcinogens even though direct causal evidence is lacking. This chapter reviews the nomenclature, chemistry, physical properties, exposure sources, toxicology, epidemiology, analytical methods, risk assessment, and regulatory aspects of various nitrosamine compounds. Occupational exposure to nitrosamines within the rubber industry is discussed in detail. Problems concerning total nitrosamine exposure in humans and the determination of cancer risks are highlighted. Additionally, industrial hygiene exposure control measures and medical surveillance pertaining to nitrosamines are discussed.