The present study evaluates the impact of a one-day challenging behaviour course on the knowledge of 59 staff (20 health, 20 social care, 19 day care) as compared with a control group (n = 73). The study found that training led to a significant increase in knowledge in the trained group on all factors but one. This was the identification of the main factors important in responding to challenging behaviour. In relation to this, staff appeared to identify only those factors either which would clearly be within their remit or which they would be more likely to use in their daily work, e.g. health staff identifying psychological approaches, day care and residential staff identifying reactive strategies. Gains in knowledge were found to be similar in those groups followed up immediately, 3–6 months and 6–12 months after training. No significant differences in scores between baseline and follow-up were found for the group who had not received training.