We reviewed studies on genotoxicity and carcinogenicity of cadmium (Cd). Salmonella typhimurium and Escherichia coli exposed to Cd did not show mutagenicity, whereas cultured mammalian cells exposed to Cd showed mutation, DNA strand breaks, and chromosomal aberrations. Carcinogenicity tests showed that exposure to Cd increased the occurrence of tumors in testis, lung, prostate, hematopoietic tissues, and injection sites. On the other hand, recent epidemiologic studies are not supportive of earlier observations on the association between Cd and prostate cancer. The US NIOSH data on a possible association between Cd and lung cancer may need reevaluation. No studies which show a positive relationship between oral Cd exposure and carcinogenesis have been reported. All available data suggest that Cd should be reassigned to IARC Group 2A (probably carcinogenic to humans) from the current Group 1.