Many people with learning disabilities engage in challenging behaviours which, behaviour analytic models suggest, are social behaviours sensitive to the actions of others in the environment. In this paper, the research literature on the behaviour of staff, especially that pertaining to interactions with people with challenging behaviours, is reviewed. Empirical evidence is found to support the hypothesis that staff actions affect clients' challenging behaviours. In addition, studies of staff behaviour show that their behaviour is often counter-habilitative. Firstly, staff spend little time interacting with clients and the quality of these interactions is often poor. Secondly, observational studies have shown that staff respond intermittently to challenging behaviours, and self-report studies indicate that many of these responses are of a nature that may reinforce such behaviours. Finally, although limited, evidence suggests that behavioural programmes for clients with challenging behaviours are rare and where they do exist they are often not carried out by staff. To date, interventions for staff behaviour (training and management approaches) have acted to change these ways of behaving but have not been founded on adequate analyses of staff action. A call is made for analyses of staff behaviour, and other implications for research and practical work with staff are discussed.