Methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE) have emerged as major infection control problems worldwide. Patients previously infected or colonized with MRSA or VRE need to be identified and often isolated as soon as they visit a health care facility. Infection control personnel usually are not aware when these patients enter their facilities. We developed a system-wide surveillance system to alert infection control personnel when patients with previous MRSA or VRE cultures from LDS Hospital have subsequent clinical encounters at any inpatient or outpatient facility at Intermountain Health Care (IHC). This paper describes this system and includes the results from an initial study on the potential epidemiological benefits provided to help improve patient care. The study found that patients with previous MRSA and VRE had subsequent encounters at 62 different IHC facilities up to 304 miles away from 1 day to over 5 years later. In addition, the new surveillance system was able to alert infection control personnel when ever these patients visited any IHC inpatient or outpatient facility.