Bouveret's syndrome is a rare disorder that causes upper gastrointestinal obstruction, typically in elderly patients with a history of chronic cholelithiasis. We present an unusual case of a 58-year-old woman with untreated vesicular lithiasis who developed Bouveret's syndrome. She presented with severe abdominal pain, nausea, vomiting, and abdominal distension. Imaging studies confirmed the presence of an impacted gallstone in the duodenum, causing obstruction. The patient underwent successful surgery with removal of the stone and repair of the bilioenteric fistula. Early diagnosis and prompt surgical intervention are essential to prevent complications such as bowel perforation and sepsis. This case highlights the importance of considering Bouveret's syndrome in the differential diagnosis of bowel obstruction, particularly in elderly patients with a history of cholelithiasis.