Background. The aim of this study was to assess the impact that Academic Detailing (AD) had on General Practitioners' use of diagnostic imaging for shoulder complaints in general practice and their knowledge and confidence to manage shoulder pain. Methods. One-to-one Academic Detailing (AD) for management of shoulder pain was delivered to 87 General Practitioners (GPs) in metropolitan Adelaide, South Australia, together with locally developed clinical guidelines and a video/DVD on how to examine the shoulder. Three months after the initial AD a further small group or an individual follow up session was offered. A 10-item questionnaire to assess knowledge about the shoulders was administered before, immediately after, and 3 months after AD, together with questions to assess confidence to manage shoulder complaints. The number of requests for plain film (X-ray) and ultrasound (US) imaging of the shoulder was obtained for the intervention group as well as a random comparison group of 90 GP's from the same two Divisions. The change in the rate of requests was assessed using a log Poisson GEE with adjustment for clustering at the practice level. A linear mixed effects model was used to analyse changes in knowledge. Results. In an average week 54% of GPs reported seeing fewer than 6 patients with shoulder problems. Mean (SD) GP knowledge score before, immediately after and 3-months after AD, was 6.2/10 (1.5); 8.6/10 (0.96) and; 7.2/10 (1.5) respectively (p < 0.0001). Three months after AD, GPs reported feeling able to take a more meaningful history, more confident managing shoulder pain, and felt their management of shoulder pain had improved. Requests for ultrasound imaging were approximately 43.8% higher in the period 2 years before detailing compared to six months after detailing (p < 0.0001), but an upward trend toward baseline was observed in the period 6 months to 1 year after AD. There was no statistically significant change in the rate of requests from before to after AD for plain-radiographs (p = 0.11). No significant changes in the rate of requests over time were observed in the control groups. Conclusion. These results provide evidence that AD together with education materials and guidelines can improve GPs' knowledge and confidence to manage shoulder problems and reduce the use of imaging, at least in the short term.