Retroperitoneal inclusion cysts are uncommon mesothelium-lined cysts seen in the pelvis of reproductive-age women. It presents as a pelvic mass or with pelvic pain and may be misdiagnosed as an ovarian malignancy. Although benign, local recurrences are common, often requiring repeated surgeries. We report a case of retroperitoneal inclusion cysts, which was diagnosed clinically as benign multilocular cyst of ovary; however, it turned out to be retroperitoneal mesothelial inclusion cyst on histopathology. A 55-year-old postmenopausal woman referred to our outpatient department with intermittent lower abdominal pain. Results of routine blood investigation and CA-125 were within normal limits. A pelvic MRI showed a cystic ovarian tumor, approximately 7 cm in diameter with numerous septated small cysts. We performed a laparoscopic surgery on April 19, 2016. First, we removed extensive adhesions on pelvic wall. After confirming no abnormalities in both ovaries, we opened the peritoneum to investigate retroperitoneal space. There was a cystic multiloculted mass firmly attached to the right ureter and the pouch of Douglas. The lesion was friable and to avoid rupture of the cyst and spillage of the cystic fluid, meticulous care was taken. Complete resection of the lesion was performed. Postoperative recovery was good and the histopathology showed benign cystic mesothelial lesion. We present this case along with a video clip.