Adult idiopathic hypertrophic pyloric stenosis (AIHPS) is a rare entity first described by Cruveilhier in 1835. There are only approximately 200 cases reported in the English literature to date. Histologically, it may be mistaken for spindle cell neoplasms such as gastrointestinal stromal tumour (GIST). Patients with AIHPS usually present with early satiety, abdominal fullness, postprandial vomiting, epigastric pain, and eructations. Adult intussusception is rare and only accounts for 5% of all intussusceptions. Gastroduodenal intussusception is one of the rare types of adult intussusception. This is more likely to occur when a benign or malignant stomach lesion acts as a lead point. We report a case of AIHPS in a 70-year-old lady presenting with gastroduodenal intussusception. An oesophagogastroduodenoscopy (OGDS) was performed, and it revealed a diffusely thickened and narrowed pyloric antrum. A contrasted computed tomography (CECT) of the thorax and abdomen showed a distended stomach with circumferential thickening of the pylorus. The pre-pyloric antrum was intussuscepting into the pylorus, and the apex is seen within the first part of duodenum. She underwent distal gastrectomy with a Roux-en-y reconstruction via laparoscopic approach and was discharged well. AIHPS is a rare condition and should be a differential in adults presenting with gastric outlet obstruction. We believe in cases of AIHPS presenting with gastroduodenal intussusception, a distal gastrectomy with reconstruction is a reasonable approach. A multidisciplinary approach is essential to obtain the best outcome.