Adenocarcinoma of the rete testis is a rare and aggressive malignancy arising from the epididymal epithelium. We present a case of a 66-year-old male who presented with left testis mass. Histopathological analysis of orchiectomy specimen was consistent with adenocarcinoma of the rete testis. Subsequent retroperitoneal lymph node dissection revealed metastatic disease not detected on preoperative PET-CT. Prior reports have suggested poor response rates to both systemic chemotherapy and radiation therapy. Aggressive surgical management of the retroperitoneum should be considered even in clinically node-negative patients given the paucity of other effective treatment regimens.