Background: Although staff attitudes towards individuals with intellectual disability (ID) whose behaviour challenges may be an important part of a positive support culture, very little research has focused on the development of training specifically designed to change staff attitudes. Positive contact is hypothesised to be an effective way to change attitudes towards stigmatised groups. Methods: We designed and developed a half day training package about the experiences of individuals whose behaviour challenges--Who's Challenging Who (WCW). The WCW package was delivered according to a manual by a trainer with ID and a professional without disability. Seventy-six staff from a variety of organisations participated in one of 10 WCW training sessions and provided data on their attitudes and empathy towards individuals whose behaviour challenges prior to the WCW training and immediately at the end of training. Staff also completed a post-training evaluation questionnaire. Results: A training package was successfully developed collaboratively with individuals whose behaviour challenges, and received very positive evaluations from staff participants. Short-term positive change was shown for empowerment and similarity attitudes, and staff empathy and self-efficacy. These outcomes were associated with small to moderate effect sizes. Conclusions: Meaningful short-term positive staff attitude changes were found and the WCW training model was shown to be feasible. More robust research designs are needed for future evaluation. In addition, the function of an attitude change intervention such as WCW within organisations' training strategies requires further development.