The effects of dietary administration of catechol (CC), paramethylcatechol (PMC) and di(2-ethylhexyl)phthalate (DEHP) were compared with that of butylated hydroxyanisole (BHA) in Syrian hamsters initiated with N-nitrosobis(2-hydroxypropyl)amine (BHP). Development of pancreatic atypical hyperplasias and adenocarcinomas in terms of combined multiplicity was significantly reduced by CC and DEHP. A similar slight but non-significant tendency was observed for BHA, while PMC was without effect. No statistically significant reduction of liver or gall bladder lesions was observed. The results thus suggest that both antioxidant and peroxisome proliferator categories of agents can inhibit pancreatic carcinogenesis in hamsters.