Multicystic peritoneal mesothelioma (MCPM) is a rare cystic proliferation most often seen in women of reproductive age with a history of prior abdominal surgery. This is a case report of an 83-year-old woman diagnosed with MCPM during an exploratory laparotomy for presumed peritoneal carcinomatosis from colon cancer. After complete removal of all visible MCPM, the patient remains free of both colon cancer and MCPM. This article reviews the literature with regards to the pathology, natural history, risk of malignant transformation, and current options for management of MCPM, including cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.