The operating room environment is not the primary source of surgical site infections (SSIs), thanks to traffic controls, efficient air flow and filtration systems, equipment draping, and good cleaning practices. Still, many members of the healthcare team take for granted that their environmental controls are working, and they may not truly understand the "hows" and "whys" of these controls. When members of your team are less aware than they should be, the chance of an SSI outbreak increases. To help you keep your staffers alert and educated, this article reviews some of the basic principles of environmental maintenance in the OR.