Background: Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is an aggressive locoregional treatment for peritoneal carcinomatosis (PC). Studies demonstrate improved perioperative and oncologic outcomes at high-volume centers. Methods: This study retrospectively analyzed all patients with PC from various malignancies who underwent attempted CRS/HIPEC at the authors’ institution from 2007 to 2017. Clinicopathologic, perioperative, and oncologic outcomes of early (2007–2012) and late (2012–2017) experience were compared, and multivariate analyses for factors predictive of perioperative and oncologic outcomes were performed. Results: The study enrolled 388 patients (157 early and 231 late). The late experience contained more appendiceal low-grade mucinous neoplasms (LGMNs; 21% vs 9%) and had a lower Peritoneal Cancer Index (PCI; 10 vs 16). Moreover, achieving a similar rate of CC-0/1 required fewer organ resections, involved shorter operations (298 vs 347 min), and had lower estimated blood loss (EBL) (400 vs 200 ml) (p < 0.05). More procedures were aborted (20% vs 3%; p < 0.01). The late experience had fewer ICU admissions (13% vs. 55%) and a lower perioperative mortality rate (0% vs 3%) (p < 0.05). In the multivariate analyses, PCI and number of organ resections were independent predictors of multiple perioperative outcomes [EBL, operating room time, intensive care unit (ICU) admission, ICU length of stay (LOS), overall LOS]. Survival was significantly longer in the late cohort (median overall survival: NR vs 31 months; progression-free survival: 22 vs 11 months; p < 0.01), even after control for tumor histology. Conclusions: At the authors’ high-volume center, with increased surgeon and institutional experience over time, perioperative and oncologic outcomes have improved significantly for patients undergoing CRS/HIPEC for PC.