We present a case of a completely isolated enteric duplication cyst in a 28-year-old man. Computed tomography showed a large complex cystic mass with curvilinear and nodular calcifications near the anterior aspect of the left kidney. It had no connection to the pancreas, stomach, small bowel, or large bowel. We found no report describing computed tomographic findings of completely isolated enteric duplication cyst in the English-language literature.