BACKGROUND Aggressive fibromatosis, also known as desmoid tumour (DT), is a locally invasive soft tissue malignancy originating from fascial planes, connective tissue, and musculoaponeurotic structures of the muscles. The symptoms greatly depend on the location and size of the tumour. METHODS A 68-year-old male patient without any comorbidities with a large, palpable mass in the abdomen underwent computed tomography (CT) of the abdomen during diagnostic examination in September 2017 in another centre. The CT scan revealed a giant intraperitoneal 30×40cm tumour without signs of infiltrating the surrounding organs and large vessels. The tumour biopsy revealed an aggressive DT. The patient was scheduled for tumour resection. Midline laparotomy was performed in the supine position under general anaesthesia. After gaining access to the abdominal cavity, 8 litres of clear ascites were evacuated. The tumour was not attached to the abdominal wall. Large omentum was freed from the DT. The perioperative finding confirmed the CT images of DT encapsulation of the medial colic artery, part of the small intestine, and transverse colon. The tumour was resected with part of the mesenteric radix, 30 cm of small intestine, and 2/3 of the transverse colon. After the DT was removed entirely, the small intestine was re-anastomosed end to end. The abdominal cavity and the liver were carefully checked for bleeding. The abdominal cavity was closed in a standard manner. RESULTS The postoperative hospital stay was uneventful. The patient was discharged on the 7th postoperative day with prophylactic low weight molecular heparin for one month. Currently, we have five months of follow-up with no signs of DT recurrence based on CT examination. The histology of the resected tumour confirmed the diagnosis of a desmoid tumour (aggressive abdominal fibromatosis). CONCLUSIONS Desmoid tumours are benign neoplasms with no metastatic potential. However, their treatment is challenging due to their aggressive growth, infiltrative behaviour, and a high tendency to recur.