An extensive tumour in a 35-year-old women with gradual swelling of abdomen. On examination, solid mass over the abdomen of 28 weeks size of gravid uterus. Tumor was fixed with irregular surface and proved to be an aggressive fibromatosis [Desmoid tumour] on histological examination. Twelve months after surgery there was no evidence of recurrent disease. This suggests that tumour resection had been successful.