Environmental cleaning in surgical settings minimizes patients' and health care workers' exposure to potentially infectious microorganisms. This article describes the implementation of an instrument designed to help nurses monitor OR environments, identify problem areas, and correct cleaning deficiencies before patient care is affected adversely. During a six-month pilot test in which the instrument was used daily to compare contamination events in rooms and on room surfaces, contamination events in the ORs decreased. These measurable outcomes helped health care workers develop strategies for proper cleaning and influenced multidisciplinary decision making about terminal cleaning issues.