Door openings have been shown to increase bacterial counts in the operating room (OR) as a result of air exchange between the OR and adjacent spaces, potentially increasing risks for Surgical Site Infections (SSIs). A deeper understanding of door opening behavior and patterns is necessary to develop interventions that will have sustained impacts. Twenty-eight surgical procedures were recorded and closely watched. Accordingly, duration, intent, and destination of people involved in all door openings were identified and analyzed with respect to operation phase (i.e., pre-incision, incision-to-closure, and post-closure phases). Results suggest that the distribution of door opening duration in the incision-to-closure phase is independent of surgery type and room layout. The door was opened by someone other than the core surgical staff around 23% of the time. There seems to be a need for improvement in communication and design efficiency to manage traffic through the OR door.