Human exposure to aromatic amines has long been associated with an elevated risk of urinary bladder cancer. Nonetheless, use of these materials has continued due to their industrial and commercial value. Commercial value, chemical reactivity and biological effect are closely linked, making it difficult to select materials that are commercially useful and safe. The chemical structure of carcinogenic aromatic amines is discussed in this paper along with some past and current sources of exposure and the overall epidemiological data supporting the carcinogenicity of these materials. The low dose effects of aromatic amines in tobacco smoke are considered. In addition, the possibility that such widely used commercial products as hair dyes may be related to urinary bladder cancer in humans is reviewed. Research questions either now being currently addressed or may potentially be addressed by the application of biomarkers to human aromatic amine exposure assessment are highlighted.