Abstract: The present study intended to study the influence of Phaseolus vulgaris beans in mammary carcinogenesis especially considering the main malignancy indicators through a histopathology study. A total of 72 female rats 50 days old were divided in three groups and hold in constant conditions temperature, light and humidity. Group B and C received 20 mg of 7, 12 dimethyl benzanthracene by gavages. All the animals were fed with the same standard food, group C were supplemented with Phaseolus vulgaris beans. The study had last for 150 days. Tumors in group C animals had lower pattern grades and lower mitotic counts despite the higher weight gain in this group. These results suggest a protective role of bean consumption in mammary carcinogenesis possibly due to fiber and oligossacharides content, especially present in Phaseolus vulgaris from “padrão tarrestre” species.