Abstract: Purpose : The teratogenic potential of cigarette smoke was evaluated by using the short term biological assay. Methods : The adults and regenerators of Hydra were exposed respectively to water-soluble and fat-soluble extracts of cigarette smoke. According to Wilby’s score method , median toxic concentration (T50) in adults and median inhibition concentration ( I50) in regenerators of the extracts were calculated. On the basis of T50 to I50 ratios , the teratogenicity was judged. Results : T50 and I50 of the water-soluble and fat-soluble extracts 159. 1 mg/ L , 29. 8 mg/ L and 14. 5 mg/ L , 3.8 mg/ L , and T50 to I50 ratios were 10. 97 and 7. 84 , respectively. Conclusion : The water-soluble and fat-soluble extracts of cigarette smoke showed teratogenesis in the Hydra regeneration assay.

Key words: cigarette smoke, extract, Hydra, teratogenesis