Peritoneal carcinomatosis (PC) in the setting of mucinous appendiceal neoplasms is characterized by the intraperitoneal accumulation of mucinous ascites and mucin-secreting epithelial cells that leads to progressive compression of intra-abdominal organs, morbidity, and eventual death. We assessed postoperative and oncologic outcomes after aggressive surgical management by experienced surgeons. We analyzed clinicopathologic, perioperative, and oncologic outcome data in 282 patients with PC from appendiceal adenocarcinomas between 2001 and 2010 from a prospective database. Kaplan–Meier survival curves and multivariate Cox-regression models were used to identify prognostic factors affecting oncologic outcomes. Adequate cytoreduction was achieved in 82% of patients (completeness of cytoreduction score (CC)-0: 49%; CC-1: 33%). Median simplified peritoneal cancer index (SPCI), operative time, and estimated blood loss were 14 (range, 0–21), 483.5 min (range, 46–1,402), and 800 ml (range, 0–14,000), respectively. Pathology assessment demonstrated high-grade tumors in 36% of patients and lymph node involvement in 23% of patients. Major postoperative morbidity occurred in 70 (25%) patients. Median overall survival was 6.72 years (95% confidence interval (CI), 4.17 years not reached), with 5 year overall survival probability of 52.7% (95% CI, 42.4, 62%). In a multivariate Cox-regression model, tumor grade, age, preoperative SPCI and chemo-naïve status at surgery were joint significant predictors of overall survival. Tumor grade, postoperative CC-score, prior chemotherapy, and preoperative SPCI were joint significant predictors of time to progression. Aggressive management of PC from mucinous appendiceal neoplasms, by experienced surgeons, to achieve complete cytoreduction provides long-term survival with low major morbidity.