['Preoperative radiation (PR) in the management of retroperitoneal sarcoma (RPS) is controversial. Concern for increased perioperative morbidity may influence the decision to recommend PR. Here we compare 30-day morbidity and mortality (M\u2009+\u2009M) after resection of RPS with and without PR.', 'Patients undergoing resection of RPS were identified using ACS NSQIP (2005-2011). Patients with known PR status within 90 days of operation were included. Univariate and multivariate logistic regression analyses were performed to identify factors associated with M\u2009+\u2009M.', 'Of 696 patients operated on for RPS, 70 (10%) underwent PR. PR patients were younger (mean 55 vs. 61 years), more frequently had hypoalbuminemia (<3\u2009g/dl; 19% vs. 10%), concomitant kidney (29% vs. 18%), or pancreas resections (11% vs. 5%), longer operations (mean 327 vs. 253\u2009min), and increased transfusion requirements (mean 4.1 vs. 2.1 units, each P\u2009<\u20090.05). Despite these differences, the M\u2009+\u2009M rate (31% with vs. 30% without PR, P\u2009=\u20090.75) was comparable between the two groups. After adjustment for confounders, no association was identified between PR and M\u2009+\u2009M.'] Is preoperative radiation for retroperitoneal sarcoma associated with increased early postoperative morbidity?