A retrospective adverse drug reaction (ADR) reporting system has been in place at Cedars-Sinai Medical Center for 7 years. Initially, the system identified 300 to 400 ADRs per year. After adding a checklist, that number increased to 750 to 850 per year, an ADR rate of about 2% of total patient admissions. To increase the ADR reporting rate, we initiated a concurrent surveillance program in conjunction with the retrospective system. In the first year of the program, the combined systems identified 1,174 ADRs. In addition, the ADR rate per 100 patient days increased to between 0.5 and 0.7, and the ADR per admission rate increased. to 4%, As a result of the more effective ADR surveillance program, the P and T Committee has additional data from which to develop guidelines and educational programs to increase ADR awareness and prevention, and thus, to improve patient outcomes.