Background: It is estimated that 35% of the US population is obese. It is unknown how obesity influences the operative and survival outcomes of CRS/HIPEC procedures. Methods: A retrospective analysis of a prospective database of 1,000 procedures was performed. Type of malignancy, ECOG, resection status, hospital and ICU stay, Clavien-Dindo morbidity, mortality and survival were reviewed. Results: 242 patients with BMI>30 (30-63.3) underwent 264 CRS/HIPEC procedures between 1991-2012. 94(38.8%) of those had a BMI>35. 136(51.7%) obese patients had appendiceal and 59(22.4%) colon cancer. Median follow up for obese patients was 52 months. Major (III /IV) and minor morbidity (I/II) was 36.6% and 28.8% for obese and 36.5% and 25.7% for non-obese patients. The 30 day mortality for obese and non-obese was 5.5% and 7.3% respectively. Median ICU and hospital stay was 1 and 9 days for both obese and non-obese. The 30 day readmission rate was similar between obese and non-obese patients 35.2% vs 30.8%. When patients were grouped by primary (colon or appendix), resection status, and grade of disease (for appendiceal) and stratified by BMI (not obese, 30-<35, ≥35) there was no difference in 30 day postoperative morbidity and mortality. When the interaction of obesity with the biology of the underlying primary was studied there was no obesity related survival differences. For obese and non-obese patients, median survival for low grade appendiceal cancer was 76 months and 107 months respectively (p=0.38) and for colon cancer was 18.1 months and 19.8 months. 5 and 10 year survival for the low grade appendiceal group was 60.5% and 33.1% for obese and 69.1% and 46.5% for non obese (p=0.38). Conclusions: Obesity does not influence postoperative morbidity and mortality of patients with peritoneal surface disease (PSD) regardless of primary. Obesity does not influence long term survival for appendiceal and colon cancer patients with PSD, and should not be considered a contraindication for the procedure.