In 50% of BALB/c mice pretreated with atropine, tongue tumours were induced by fortnightly application of DMN-OAc (2 mg/kg) on the tongue. When DMN-OAc + TPA was used for the initiation-promotion protocol, tumours were observed on the tongue, the site of application, in only 10% of animals. In the same group, stomach tumours were obtained in 63% of mice, denoting that initiation-promotion could be successfully used to induce stomach tumours. Using a protocol of DMN-OAc + chilli as a promoter, we observed induction of stomach tumours. The promoter effect of chilli extract was also seen in the BHC-induced hepato-carcinogenesis system. It thus appears that, in BALB/c mice, chilli acts as a promoter in stomach and liver carcinogenesis.