This evidence-based study answers the clinical question: Can a programmatic approach to environmental hygiene improve the thoroughness of cleaning in the OR? Environmental hygiene is an important but sometimes overlooked component of safe patient care in the OR. Evaluations of OR cleanliness are usually based on subjective visual observation. A study was conducted at four hospitals with a combined total of 72 ORs to determine whether focused training on best practice processes, products, and tools for effective OR cleaning and disinfection, the use of an objective environmental monitoring tool, and staff performance feedback would improve the thoroughness of disinfection cleaning (TDC). Pre- and post-intervention assessments of TDC were conducted for end of case and terminal cleaning in the OR. TDC was evaluated with a transparent, fluorescent marker and handheld ultraviolet (UV) light used to determine if high touch objects had been contacted by a wet disinfection cleaning cloth, as demonstrated by complete removal of the fluorescent mark. In the pre-intervention period, baseline TDC was evaluated. During the intervention period, staff were trained on high touch objects and best practices for EH and provided with processes and tools to improve TDC. In the post-intervention period, TDC was again evaluated. Preliminary results indicate that end of case TDC in the pre-intervention period averaged 23% while post-intervention end of case TDC averaged 64% for a 41% overall improvement. Terminal Cleaning TDC in the pre-intervention period averaged 40%, while Terminal Cleaning TDC in the post-intervention period averaged 55% for a 15% overall improvement. These results were obtained after one cycle of training, monitoring, evaluation, and staff feedback. A programmatic approach to environmental hygiene training, processes, tools, environmental monitoring, and performance feedback can improve end of case and terminal cleaning in the OR.