The Müllerian ducts differentiate into reproductive organs in females and gradually degenerate in males. Therefore cysts originating from its remnants are mostly seen in males, aged 20-40 years, and preferably in the pelvis. As they are mostly found near the bladder and behind the prostate, they can clinically cause dysuria, frequent urination, urinary retention and abdominal mass. Abdominal mass is relatively large in size and compresses the rectum, resulting in intestinal obstruction, such as difficulty in urination and defecation. They vary in size as seen by the naked eye. Huge cysts may contain 5000 ml of fluid, mostly unicompartmental, containing clarified grass-green or chocolate-like fluid. The fluid in the cyst may contain red blood cells, white blood cells, cholesterol and fat, but no sperm. In case of Müllerian duct, it should be differentiated from Müllerian ductogenic tumors and epithelial cysts of Müllerian duct.