Malignant peritoneal mesothelioma (MPM) is a rare and lethal disease of the peritoneal lining, with high variability in biologic aggressiveness. Morbidity and mortality of the disease are related to progressive locoregional effects within the abdominal cavity, such as distention, pain, early satiety, and decreased oral intake that can ultimately lead to bowel obstruction and cachexia. The standard of care for patients with resectable disease remains cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC), with potential survival outcomes greater than 5 years in appropriately selected patients. Patients with inoperable MPM can be offered systemic treatment, although the disease is usually refractory to standard chemotherapic regimens. Patients with MPM should be treated at high volume centers with strong consideration for inclusion in tumor registries and clinical trials. In 2020, research will continue to explore promising genetic and immunologic targets and focus on refinement of surgical methods to optimize CRS-HIPEC approaches.