Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare tumor of the soft tissue, usually located in lower extremities. There are rarely tumors reported in other anatomic locations. Herein, we report retroperitoneal PHAT in a male patient. A 41-year-old man was referred to our clinic due to an incidentally found retroperitoneal mass. Computed tomography (CT) scan showed a solid hypoechoic lesion containing fat component and calcified elements measuring about 80*72*45 mm in the right lower quadrant (RLQ) of the abdomen. Magnetic resonance imaging (MRI) showed circumscribe lesion measuring about 60 x 48 mm with partial enhancement and fat component. In pelvic exploration, a large mass was found that had encased the right external iliac artery and vein. Therefore, the mass and its surrounding iliac vessels were excised and removed en block. Then, the external iliac vessels were reconstructed with Gortex graft. No recurrence was found in 1 month and 3 months post-operation follow up. We report a pelvic retroperitoneal PHAT as a rare location of this tumor. It seems that PHAT must be considered in differential diagnosis in patients with soft tissue tumors in the pelvic cavity.