Contributing factors culminating in any surgical site infection (SSI) potentially involve a large number of endogenous (patient related) and exogenous (non-patient related) possibilities. We cannot expect to ultimately be successful in preventing these infections unless we can recognize the diverse origins of wound contamination and understand how normal immune defenses can be thwarted, allowing infection to occur. Only by understanding these factors can we effectively implement means of eliminating their impact. This course focuses on the exogenous factors potentially contributed by surgical team members, the apparel and devices they use, the techniques they practice and the environment in which they operate.