Gallstone ileus is an unusual cause of small bowel obstruction, in general, let alone after cholecystectomy. It occurs in patients with chronic calculous cholecystitis and gallstones who develop a cholecystoduodenal fistula over time. The diagnosis is made based on clinical presentation and examination findings and is confirmed with the use of radiological modalities, such as computed tomography (CT) scan, which has been proven to be the most sensitive investigation in diagnosis. Here, we present a case of gallstone ileus that occurred 25 years after laparoscopic cholecystectomy. CT scan on admission showed adhesional small bowel obstruction given the patient's previous abdominal surgery. The patient was managed conservatively as per guidelines for the management of adhesional small bowel obstruction for 72 hours. Obstructive symptoms did not resolve despite all conservative measures, and a gastrografin challenge showed no contrast reaching the colon. Hence, the patient underwent an exploratory laparotomy to manage his ongoing bowel obstruction. Laparotomy revealed gallstone ileus as the cause of obstruction. This case highlights the importance of considering gallstone ileus in the differential diagnosis for patients who present to the emergency department with small bowel obstruction even years after cholecystectomy. Post-cholecystectomy gallstone ileus is very rare with very few cases reported in the literature. This condition poses diagnostic challenges both because of its rarity and because the gallbladder had been previously removed. A high index of suspicion by the surgeon is needed for diagnosis.