The BTS/SIGN British Guideline on the Management of Asthma was published in February 2003 (4). If health outcomes are to be influenced successfully, dissemination of the guideline and implementation of recommendations is essential. We report the dissemination activities undertaken during the 18 weeks following the guideline launch. To facilitate implementation a range of educational materials were produced reflecting the key messages from the guideline. In addition to postal mailing of the guideline to appropriate healthcare professionals, both educational materials and the guidelines were made freely available from the BTS and SIGN websites. In total, 135,710 copies of the guideline and 90,198 copies of the Quick Reference Guide were downloaded in the first 18 weeks, representing a considerable increase over the number of copies of the 1997 guidelines disseminated by mailing alone. Large quantities of educational materials were downloaded with many used for teaching purposes. An on-line survey suggested that most respondents rated the materials as useful or very useful. Using websites to disseminate guidelines is a cost-effective method of informing health professionals of their content and is a more active process than the passive receipt of mailed copies. The availability of interactive educational materials for use in teaching appears to have been popular.