We examined a 31-year-old woman with a solid mass in her left axilla. Physical examination and ultrasonography confirmed a 2 cm well-defined mass. Fine needle aspiration biopsy suggested fibroadenoma of breast. Excisional biopsy revealed benign phyllodes tumor of the ectopic breast tissue. Phyllodes tumor in ectopic breast tissue is an extremely rare occurrence. Only nine cases have been reported, including tumors of the vulva, inguinal region and axilla. This is the second case in the axillary region.