Surgical site infections (SSI) in the postoperative period represent the sword of Damocles in surgery. In spite of the medical progress in recent years these infections cannot always be avoided and occur in 25% of all nosocomial infections in Germany. They also generate up to 50% of the required costs in this context. The consequences vary from extended duration of hospitalization to elevated mortality. The degree of contamination of surgical wounds is of great importance as well as the patient's immune status and comorbidities. Prevention of infected surgical wounds is essential and important measures should begin even prior to the surgical procedure. In addition, during and following the surgical procedure several standards have to be followed. Rapid confirmation of diagnosis and correct management of surgical site infections are essential for the course of the disease. This study provides information on development, prevention and therapy of surgically infected wounds.