Anticarcinogenic activity of astaxanthin-containing egg yolks (designate AEY) was investigated for 7,12-dimethylbenz[a]anthracene (DMBA)-induced two stage mouse epidermal carcinogenesis. Female ICR mouse (6-7 weeks of age) were house in a humidity-and-temperature-controlled facility and subjected to feed and water ad libitum. AEY (10 mg/0.2 ml acetone) was painted on the back of mice 7 days, 3 days and 5 min before DMBA treatment (50 nmole/0.2 ml acetone). One week later after DMBA treatment, 6 ${mu}g$ tetradecanoyl 12-phorbol 13-O-acetate (TPA) dissolved in 0.2 ml acetone was applied on the mouse twice weekly over a period of 22 weeks. No sample was given to control mice. Control egg yolk (CEY) and astaxanthin-containing oil (designate AO) from Phaffia rhodozyma were used as positive controls. Mouse treated with AEY exhibited 10 tumors per mouse whereas control mouse exhibited 15 tumors per mouse, the fact that 33% reduction of tumor per mouse by AEY treatment. Tumor incidence was also reduced to 15% by AEY treatment when compared to that of control group. Such effects were also seen in CEY and AO treatment groups, but leaser extent. AO gave reduction of food intake and body weights relative to those of AEY and CEY, indicating toxicity of AO. These results suggest that AEY exhibits anticarcinogenic activity for DMBA-induced mouse epidermal carcinogenesis.