AbstractBackgroundComplete cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy is the standard of care for mucinous appendiceal neoplasms with peritoneal metastases. Despite many publications regarding selection factors favoring a complete CRS, incomplete CRS does occur. Patients with an incomplete CRS are the focus of this manuscript.MethodsA retrospective analysis of prospective, histologic, and perioperative data was performed. Overall survival was the endpoint for the numerous assessments. Judgments regarding when to and when not to proceed with an incomplete CRS were sought.ResultsFrom a database of 949 patients who underwent an index CRS for appendiceal mucinous neoplasm, 264 patients (27.8%) had an incomplete CRS. The median overall survival was 1.8 years. Low‐grade histopathology and absence of tense ascites or bowel obstruction were significantly associated with increased overall survival. More extensive surgery suggested a more favorable outcome.ConclusionsWhen a surgeon is confronted by a procedure that will inevitably end with an incomplete CRS, a current trend is to close quickly and always avoid complications. Patients with low‐grade neoplasms who present in the absence of tense ascites or bowel obstruction may gain years of survival by surgical reduction of tumor burden.