Toad skin extract cinobufatini study has been focused on anticancer activity, especially apoptosis-inducing activity by bufosteroids. The present study examined effect of the toad skin extract on cancer cell migration into model stromal tissues. Human breast carcinoma cell line MDA-MB-231 was incubated in the presence or absence of toad skin extract on a surface of reconstituted type I collagen gel as a model stromal tissue allowing the cells to migrate into the gel. Frozen sections were microscopically observed after azan staining. Data showed a decrease of cell number in a microscopic field and shortening of cell migration into the model stromal tissue in a dose dependent manner. This suggests that toad skin extract may possess migration-preventing activity in addition to cell toxicity such as apoptosis-inducing activity. The multifaceted effects including apoptosis-inducing and cancer cell migration-preventing activities would improve usefulness of toad skin extract cinobufatini as an anticancer medicine.