Lipomas of the colon are rare but clinically important conditions that require suitable evaluation for guiding appropriate therapy. The majority of lipomas arise from the submucosal layer in the ascending colon, especially near the ileocecal valve, which causes difficulties in diagnosis. Giant lipomas may be misinterpreted as a premalignant adenomatous polyp, particularly when arising in the left colon. A 38-year-old man presented with manifestations including hypogastric pain, constipation, loss of appetite and weight, accompanied by anaemia, nausea, vomiting and haematochezia. Colonoscopy revealed a large submucosal polyp about 5 x 4 cm, which was located at the splenic flexure of colonic. Surgery detected an oval polypoid tumour measuring 70 x 50 x 45 mm in size, having a pedunculated appearance and a stalk diameter of 20 mm. Histopathologic examination of the biopsy from the lesion confirmed diagnosis of a giant submucosal lipoma. In our experience, most giant colonic lipomas are found to be sessile and occur in the ascending colon in older patients. Herein, we report a pedunculated tumour in a 38-year-old male located in the splenic flexure of colon.