Transgenic mouse models have been introduced and accepted by regulatory bodies as an alternative to carcinogenicity assay models to predict and evaluate chemical carcinogens. The recent research outcomes in transgenic mouse models have made progressive advances in the understanding of chemical carcinogenesis and the evaluation of potential human carcinogens. However, these models still remain to be insufficient assay systems although the insufficiencies have been recognised and are being resolved. Based on up to date information from literature, this review article intends to understand currently accepted transgenic mouse models, issues arising from study design, interpretation of the study, results of validation project and their cancer prediction rate, and further perspectives of cancer assay models from the regulatory view point.