The Angelchik antireflux prosthesis is a silicon gel-filled, doughnut-shaped device with a tantalum tie strap that wraps around the gastroesophageal junction after reduction of a hiatal hernia. If dislodged, this prosthesis may produce a confusing picture on computed tomography, as it is of soft tissue density and may mimic a mass lesion. The computed tomography appearance of a normally placed prosthesis is demonstrated, and a case of prosthesis dislodgment diagnosed by computed tomography is reported.