INTRODUCTION: To determine if an evidence-based implementation (EBI) could lead to the successful implementation of evidence based care for adult asthma in small rural district hospitals. METHODS: A controlled trial involving eight small rural hospitals (four each in the study and control groups) was conducted. Retrospective pre-intervention audits were conducted at all eight hospitals for 7 months (1 January 2004 to 31 July 2004) and evidence-practice gaps identified. An EBI was then used to implement established guidelines for the management of asthma in the study hospitals. Post-intervention audits were then performed over a period of 7 months (1 October 2004 to 31 April 2005). RESULTS: There were 52 presentations of asthma in the study hospitals in the pre-implementation phase and 47 post-implementation. The corresponding numbers for the control hospitals were 46 and 42 respectively. There were no statistically significant differences in the severity between the groups. Following the EBI there were significant improvements at the study hospitals for the documentation of severity (8% to 62%, p <0.001), use of spirometry (12% to 62%, p <0.001) and the use of written short-term asthma plans (9% to 26%, p = 0.05). There was a decrease in use of ipratropium in mild asthma (44% to 30%, p = 0.228), an increase in the use of systemic steroids (61% to 72%, p = 0.255) and no change in prescribing antibiotics for afebrile patients with asthma (21% to 21% p = 0.956). There was no significant change in practice at the control hospitals except for a decrease in the use of systemic steroids (48% to 21%, p = 0.011). For the six clinical indicators aggregate there was a significant increase in compliance with guidelines at the study hospitals (36% to 62%, p < 0.001) but no change at the control hospitals (31% to 31%, p = 0.970). CONCLUSION: The pre-intervention audits demonstrated low levels of compliance with asthma guidelines across six clinical indicators. An EBI significantly improved compliance across these six indicators, and no improvement was noted in the control hospitals. This study demonstrates that an EBI can alter clinical practice in small rural district hospitals.