Infections with multi-drug resistant organisms (MDROs) are a steadily increasing threat to inpatients as they move through the hospital. We constructed a computerized reminder system, integrated with existing data sources maintained by the infection control service. We tested the hypothesis that computerized reminders from a centralized infection control expert system can improve rates of barrier isolation in patients with MDROs. Immediately after institution of this reminder system, isolation of eligible ward patients increased from a baseline rate of 33% to 95% (p<0.0001). The median time to isolation decreased from 16.6 hours to 0 hours, indicating that the majority of patients post-intervention had isolation orders written prior to arrival on the ward. We conclude that a computerized reminder system can dramatically increase the clinical impact of data sources maintained by hospital Infection Control services.