Introduction: Deep neck infections show high levels of morbidity and mortality. Therefore, the diagnosis and treatment of such infections should be done as soon as possible, so as to avoid complications. The lateral cervical plain radiography is widely used in the diagnosis of cervical abscesses, despite it can show some false results. Objective: This paper reports a case of an esophageal foreign body. The lateral cervical plain radiography induced a misdiagnosis of retropharyngeal abscess. The limitation of such diagnostic method is discussed. Report: A 76-year-old woman searched medical evaluation in the emergency service complaining of progressive dysphagia and pain during swallowing for three days, along with fever. She was submitted to a lateral cervical plain radiography, which was compatible to retropharyngeal abscess. A computed tomography was performed for surgical planning, but it showed an esophageal foreign body that was removed by means of a digestive endoscopy. It was a peace of meat. Conclusion: Despite widely used, the lateral cervical plain radiography may show false positive and false negative results. In the diagnosis of a cervical abscess, a computed tomography is preferred.