Aggressive fibromatosis is a rare mesenchymal benign tumor characterized histologically by proliferation of fibroblasts and myofibroblasts with marked production of intercellular collagen. Predominant low signal intensity on all pulse sequences is said to be characteristic of, but not specific for, aggressive fibromatosis. The principal role of imaging in the management of aggressive fibromatosis is preoperative planning an the detection of recurrence or disease progression in nonsurgically managed patients.