Fibromatosis can be classified in two groups: Superficial fibromatosis without capacity for infiltration and deep fibromatosis with variable capacity for infiltrative growth. One of the deep fibromatoses is aggressive fibromatosis which is a local infiltrating process never known to metastasize. Two cases of aggressive fibromatosis are presented and histological characteristics and prognosis are reviewed. Once the diagnosis aggressive fibromatosis is established, surgical removal of the lesion by large excision is the only sufficient treatment.