Phyllodes tumors represent a particular class in breast pathology. They are defined as bi-tissue, fibro-epithelial tumors, similar to fibro-adenomas, but their connective tissue component is greatly predominant. They are infrequent as they represent only 3% of breast tumors. They mainly occur during the premenopausal period, since alteration of the hormonal balance may play a role. The authors feel that they represent only a type of the evolution of the fibroadenomas with a relationship, in time, following the sequence: fibroadenomaphyllodes tumor-sarcoma. The diagnosis is exclusively made by histology and there is no pathognomonic sign, whether it is clinical or mammographic. The course is essentially characterized by the possibility of local recurrences, sometimes numerous, and by the occurrence of metastases in case of malignant phyllodes tumor. These two possibilities are correlated with the histological stage of the tumor. The treatment is definitely surgical, possibly mastectomy in case of large or aggressively active tumor.