Desmoid tumor of the breast is a rare lesion. So far only 8 cases in which the tumor origin was linked to a breast implant have been published. Whether there is an etiological relation to the silicone implant or if it is pure coincidence is not evident at this time. We present the case of a 24-year-old female with congenital asymmetric breasts who underwent breast augmentation in our division on the left side and 15 months later had a breast reduction on the other side. Nine years after the first operation we found a suspicious lesion on the side of the breast implant. The histological result of the excisional biopsy showed an aggressive fibromatosis "arising from" the capsule around the silicon implant. We discuss the possible association of breast implant and desmoid tumor of the breast and evaluate the diagnostic and therapeutic options for desmoid tumors of the breast.