One component of the Surgical Care Improvement Project (SCIP) is the prevention of surgical site infections (SSIs) by: 1) timing the administration of prophylactic antibiotics (PAs) within 1 hour of incision; 2) using approved PA regimens; and 3) discontinuing PA within 24 hours. We sought to evaluate institutional compliance with SCIP recommendations in patients undergoing elective colorectal surgery and determine whether they affected the incidence of SSI. One hundred four elective colorectal cases were reviewed. In 58 patients (56%), PAs were administered within 1 hour of incision. In 71 cases (68%), the PA choice was considered compliant. There were a total of 12 SSIs (11.5%) overall. The incidence of SSI was significantly higher in cases in which PAs were not administered within 1 hour of incision (10 of 46 or 22% vs two of 58 or 3.5%, P = 0.005). There was no significant difference in the incidence of SSI in patients who received compliant versus noncompliant PA (12.7% vs 9.1%, P = 0.75). Timely PA administration significantly reduces the incidence of SSI in patients undergoing elective colorectal surgery. Efforts should focus on ensuring that PAs are given in a timely manner to reduce SSI in colorectal surgery.