Aggressive fibromatosis is the name for uncommon soft-tissue neoplasms arising within musculoaponeurotic tissue. They show benign histologic features but have an aggressive local behaviour and frequently recur after surgery or radiation. A 48-year-old black woman presented with recurrent aggressive fibromatosis after primary radiotherapy in the left temporal fossa involving the base of the skull. The patient received interferon alpha2a subcutaneously for 6 months. A slow but steady reduction of the tumour was observed, and pre-existing symptoms disappeared.