The Chicago Consensus Working Group provides multidisciplinary recommendations for the management of appendiceal neoplasms specifically related to the management of peritoneal surface malignancies. These guidelines are developed with input from leading experts, including surgical oncologists, medical oncologists, pathologists, radiologists, palliative care physicians, and pharmacists. These guidelines recognize and address the emerging need for increased awareness in the appropriate management of peritoneal surface disease. They are not intended to replace the quest for higher levels of evidence. Cancer 2020;126:2525-2533.