The timely dissemination of new medical information to the practicing physician has been identified as a problem. To examine the magnitude of this problem and useful strategies for correction, we surveyed primary care physicians to determine their knowledge of the Hypertension Detection and Follow-up Program, a recent clinical trial with important treatment implications. Forty percent of family physicians (44/110) were aware of the study within two months of publication, and 63% of internists (114/182) learned of it within six months. Eighty percent of the family physicians and 50% of the internists listed medicine journals as the source of their knowledge, while 40% of the internists learned of it from continuing medical education (CME) courses. These findings indicate that rapid dissemination of new information can occur when relevant journals are used and that CME courses also provide a timely and effective means of dissemination.