Background: The working culture surrounding challenging behaviour may have a strong effect on staff behaviour. As a first step to influencing staff talk about challenging behaviour, the aim of the present study was to explore whether a 1-day training workshop could have an effect on staff causal explanations. Methods: Fifty-four front line staff, in six separate groups, completed an adapted version of the Self-Injury Behavioural Understanding Questionnaire (SIBUQ; Oliver et al. 1996) both before and after a 1-day training workshop. The workshops were based on principles of Applied Behaviour Analysis. The SIBUQ comprised questions about causes of challenging behaviours presented in 11 short scenarios. The four possible response options for each scenario reflected behaviourally correct, behaviourally incorrect, internal emotional, and internal organic causal explanations. Results: The number of correct behavioural causal hypotheses increased significantly from pre- to post-training. The proportion of incorrect causal explanations that were behavioural in orientation also increased significantly from pre- to post-training. Conclusions: Staff causal explanations for challenging behaviour can be changed using a relatively brief intervention. Further research is needed to establish whether such changes can be used to influence working culture in challenging behaviour services.