We present the radiological findings of gastric and duodenal duplications in four adults, in whom abdominal ultrasound, endoscopic ultrasound (EUS), and CT were primarily used for diagnosis. The diagnosis was surgically confirmed in all cases. Preoperative diagnosis of duplications was possible with ultrasound in three patients, in whom CT showed a nonspecific cystic structure. Ultrasound demonstrated a pathognomonic multilayered wall appearance suggestive of a digestive origin, including an echogenic inner mucosal layer and a hypoechoic muscular layer, better appreciated using EUS in one patient. In one case, digestive origin was confirmed by direct visualization of a peristaltic activity within the cystic wall after water ingestion. In the last patient, a non-specific heterogeneous mainly solid mass of the esophagogastric junction was found to be an adenocarcinoma arising from a duplication on the histological analysis of the surgical specimen.