Background A range of factors have been suggested as determinants of staff behaviour in the context of working with people with challenging behaviour. The purpose of this study was to evaluate whether a typical challenging behaviour staff training course had an effect on staff feelings of efficacy, their negative emotional reactions to challenging behaviour, and their causal beliefs.Methods Forty‐eight staff attending a 3‐day training course on understanding challenging behaviour and managing stress were assessed pre‐training and at a 3‐month follow‐up. Questionnaires assessing self‐efficacy, emotional reactions and causal beliefs were used.Results Perceived self‐efficacy in dealing with challenging behaviours increased significantly from pre‐ to post‐training. There were no significant changes in either emotional reactions to challenging behaviours or causal beliefs.Conclusion In common with previous research, there was a sizeable impact on staff confidence and efficacy after a 3‐day training course. Given the potential significance of emotional reactions both in terms of staff behaviour and their psychological well‐being at work, more research is needed to explore how these reactions might best be dealt with in staff training interventions.