Introduction: The surgical site infection risk index (SSIRI) includes three risk factors for surgical site infection (SSI): potential for surgical contamination, duration of surgery, and patient's ASA score. A patient having a preoperative American Society of Anesthesiologists (ASA) score of III, IV or IV; a surgery classified as either contaminated or dirty-infected; an operation with duration of surgery more than T hours, where T depends on the surgical procedure being performed are considered in risk of SSI. The SSIRI can be used as a method of postoperative surveillance. The aim of this study is to analyze the applicability of the SSIRI to patients undergoing cardiac, neurologic and orthopedic surgery.