Many nitrosamines are carcinogenic, mutagenic, teratogenic, and acutely toxic in a variety of animals. They are a suspected cause of cancer in humans. Studies of in vivo or in vitro production of nitrosamines, estimation of human nitrosamine exposure, and pharmacological and biochemical studies are all hampered by the lack of reliable inexpensive analytical methods for identifying and determining nitrosamines in complex matrices. Present knowledge suggests that differential-pulse polarography would provide an attractive alternative or complement to the gas chromatographic-mass spectrometric techniques now commonly used. It is proposed to investigate the application of differential pulse polarography to analysis of biological materials for a variety of nitrosamines.