A 27 year-old married woman was admitted due to pain in lower abdomen for 7 days. USG revealed a multilobbed and multiloculated cyst in the left lower quadrant. During laparotomy, the parietal peritoneum was found thick. It was opened. A cystic lesion containing straw colored fluid was found. loculi were broken. Biopsy was taken. She had amenorrhoea for last one year.