We report the frequency of door-opening (“theatre traffic”) in orthopaedic operations at three metropolitan hospitals with different theatre policies. Published studies have correlated “theatre traffic” with airborne bacteria levels, which have been associated with raised wound infection rates. Hospital A had one scoliosis operation and two hip replacements, Hospital B had one knee revision and one knee replacement. Hospital C had one scoliosis operation. A second scoliosis operation was performed at Hospital C after “theatre traffic” education and door signage discouraging entry. One pair of surgeons performed the scoliosis operations and a different pair did the hips and knees. Hospital A is private and Hospitals B and C are public. The scoliosis operation in Hospital A (private) had an average door opening rate of 0.45/min compared to the same operation in Hospital C (public) with an average door opening rate of 1.0/min. The two hip replacements in Hospital A (private) had an average rate of 0.43/min and 0.51/min while the knee revision and knee replacement in Hospital B (public) had average rates of 0.91/min and 0.77/min respectively. Of concern is the total number of door openings that result from this rate of “theatre traffic”. In the Hospital C (public) operation the total number of door openings equalled 140 over the course of the scoliosis operation. In Hospital B the total number of door openings for the knee revision was 169 and the knee replacement was 72. In contrast, for Hospital A (private) the total number of door openings for the scoliosis operation was 73 and the two hip replacements equalled 30 and 36. The second study at Hospital C after staff education revealed a 35% decrease to 0.65/min. There was a difference in “theatre traffic” between private and public hospitals for the same or similar operations. Staff education and door signage dramatically reduced “theatre traffic” in Hospital C. Surgeons and theatre staff need to be aware of “theatre traffic” and its influence on infection rates.