Duodenal lipoma is a very rare entity with limited case reports present in literature. But duodenal ampullary lipomas are even more rare in nature. Owing to the recent advances in endoscopy and modern imaging techniques, more cases are being diagnosed and treated. However, challenge lies in performing a less invasive and least morbid procedures to treat them surgically in such complex location of tumour. To study the diagnosis and treatment of duodenal ampullary lipoma in a young male patient and challenges faced during surgical management. A 15-year-old young boy presented to us with complaints of intermittent upper gastrointestinal bleed and jaundice since last 2 months. At admission, his serum haemoglobin was 3 g% for which he was transfused 3 units of packed blood cells for optimization. On further evaluation, CT scan abdomen revealed 71 × 49 mm large heterogeneous mass in D3 segment of duodenum causing duodeno-duodenal intussusception involving D1 and D2 segment along with ampullary region with mass being the lead point. There was compression of CBD with dilatation measuring 11 mm in diameter and mild IHBR dilatation. UGIE revealed narrowing at D1–D2 junction due to polypoidal lesion with overlying smooth mucosa with no active bleeding point identified. His blood parameters were normal except for low haemoglobin (before blood transfusion) and total serum bilirubin of 2.3 mg/dl.He was optimized for surgery and underwent exploratory laparotomy with duodenotomy at D2 with mass excision of 7 × 5 cm sessile polyp with base over ampulla followed by plastic repair of sphincter of Oddi (pancreas preserving procedure). He was started on oral liquids on POD 3 and was discharged on normal diet by POD 7 with an uneventful recovery. Result of histopathological report revealed, on gross cut section, the presence of mass of 7 × 5 × 3 cm size with smooth mucosa and fibrofatty tissue. On microscopic examination, diagnosis of submucosal lipomatous polyp was made. Our case report indicated duodenal ampullary lipoma is extremely rare entity. The symptoms are nonspecific and CT scan abdomen is the first investigation of choice for diagnosis. The treatment depends on the patient’s condition as well as the size and position of the tumour. In our case report, the tumour base was exactly at the level of ampulla where we performed complex procedure of local excision of mass with sphincteroplasty avoiding major Whipple procedure for such benign condition. It provided rapid postoperative recovery to the patient.