Background <p>Deep infiltrating endometriosis is a subtype of endometriosis. A case of retroperitoneal endometriosis surrounding the ureter and forming a pelvic mass is relatively rare.</p> Case presentation <p>A 26-year-old woman was admitted to our department because of unbearable dysmenorrhea and dizziness. CT scan revealed a pelvic mass on the right side of the pelvic cavity. The pain did not alleviate even she received symptomatic treatments. She finally underwent a emergency laparoscopic exploration and a pelvic mass surrounding the right ureter was found during the surgery. We removed the mass successfully with the help of a urologist by inserting a right ureteral stent at last. A retroperitoneal endometriosis was diagnosed by postoperative pathology and GnRh was administered afterwards to prevent reoccurrence.</p> Conclusion <p>We herein present a rare case of DIE—a retroperitoneal endometriosis and describe the process of the laparoscopic management. For retroperitoneal masses closely adherent to the pelvic wall, clarifying the course of the ureter is of great importance, and collaboration with urologic surgeons may be necessary when needed. Because there is no-specific imaging features, the benign or malignant nature of the mass might be suspected before surgery.</p>