BACKGROUND Primitive neuroectodermal tumors (PNETs) occur predominantly in childhood preferentially in the soft tissues of the lower extremity and the paraspinal region. We present here a rare case of a PNET of the kidney in an adult. METHODS A tumor adjacent to the right kidney was detected by ultrasound coincidentally at a routine check-up in a 46-year-old woman with irritable bowel syndrome in her medical history. The patient had no clinical signs. Contrast-enhanced computerized tomography scan of the abdomen demonstrated a highly vascularized renal tumor. A retroperitonealectomy with en-bloc resection of the kidney was performed, and histopathological work-up showed a primitive neuroectodermal tumor of the kidney with the characteristic translocation t(11;22)(q24;q12). CONCLUSIONS This tumor entity must be accurately distinguished from other renal neoplasms because of the prognostic and therapeutic impact.