An experimental model allowing comparative studies of growth kinetics of autochtonous tumours with differentiated histology was investigated. Epithelial and mesenchymal tumours were chemically induced in mice. The distribution of parameters defining the growth of these two tumour types was first studied. Then, the correlations were calculated between the three following paired parameters: doubling times, defined during the whole growth period, latent tumoral period and survival times. The results confirmed the initial hypothesis that tumour growth kinetics were related to histological character. The study showed that there was a significant difference between growth rates, maximum sizes and survival delays respectively presented by sarcomas and carcinomas. Owing to the slow growth rate of these autochtonous tumours, this experimental model is a very interesting tool to investigate various therapeutic protocols for human beings.