Background: Positive behavioural support is increasingly viewed as the preferred service approach for people who challenge, but skills are insufficiently widespread. The need for effective staff training has been highlighted as a key factor in high quality service provision, with investigators recommending a multidimensional approach to increase effectiveness and produce changes in work performance. Method: Attitudes and knowledge of registered (qualified nurses) and non-registered (unqualified nursing assistants) staff in specialist health care services were assessed via self-completion questionnaires before and after the delivery of a newly accredited taught course in PBS and at a 1-year follow-up. Results: Significant increases in knowledge were evident immediately after the training for both groups, with further increases evident over time for the non-registered staff who completed the qualification. Initial changes in attributions immediately after training reverted to baseline levels over time. Enduring change occurred in perceived confidence, which significantly increased both for registered and non-registered staff. Conclusions: The training had a positive effect on knowledge and perceived confidence but little enduring effect on attributions or emotional responses. The importance of training conducted in conjunction with allied changes in organizational systems to ensure ongoing management attention is discussed.