Background: Clinical management guidelines (CMGs) have been developed to standardize physician practices and ensure safe and cost-effective patient care. In June 1996, evidence-based CMGs were initiated at our urban Level I trauma center. This study compares physician compliance with two such CMGs before (PRE) and after (POST) the institution of continuous surveillance by a clinical resource manager. Study Design: For 2 months PRE resource manager surveillance hospital records were reviewed retrospectively for compliance with two CMGs. POST data were collected prospectively for 2 months by the resource manager, who alerted practitioners to deviance from CMGs to justify or document therapy alternatives. The CMGs studied addressed deep venous thrombosis and stress ulcer prophylaxis. "Under" or "over" therapy described that which fell short of or exceeded guidelines. Data were analyzed by chi-square; p < 0.05 defined statistical significance. Results: Compliance with the CMGs was 48% PRE and 74% POST (p = 0.001). All noncompliant instances POST land none PRE) were altered or justified. Deep venous thrombosis and ulcer "over" therapy was significantly higher PRE (19% versus 2%, p = 0.003; 49% versus 19%, p = 0.001), resulting in $22,760.35 in costs. There was no difference in pulmonary embolism or gastrointestinal bleed rate (1%) PRE to POST. Conclusions: The use of a clinical resource manager empowered to monitor and coordinate physician behavior improves compliance with CMGs. Further study is warranted to validate resultant outcomes benefit, specifically cost-effectiveness and duration of the need for such a program. (J Am Coll Surg 1999;189:533-538, (C) 1999 by the American College of Surgeons).