The aim of this monograph is to discuss the statistical bioassay of experimental carcinogenesis. The interest in the of the cancer risk assessment has led to various statistical lines of thought, due to different intrinsic biological background and supported by the appropriate statistical analysis. The biological insight (cell proliferation, mechanism of inhibition in mutagenesis and carcinogenesis) of a cancer risk assessment has not been tackled. Emphasis was given to the statistical models considered in the literature in the area of experimental carcinogenesis as well as on the dose dependent models. Moreover, an optimal experimental design approach is discussed, for evaluating the percentiles of a distribution.