The present study aimed to explore the applicability of the attribution model to social workers' attributions towards clients with dual diagnosis of intellectual disability and psychiatric illness. Specifically, the study examined the relations between social workers' attribution of responsibility, causality, stereotypes of dangerousness, their emotional reactions and behavioural reactions towards clients with dual diagnosis.Social workers (N = 279) completed questionnaires measuring attributions of responsibility, causation and dangerousness, and reported on their emotional and behavioural reactions to clients diagnosed with DD.Most social workers reported high levels of helping behaviours. The strongest predictor of discriminatory behaviours was the stereotype of dangerousness. Social workers who reported feeling less anger and more pity towards clients with DD tended to report higher levels of helping behaviour. But contrary to attribution theory, fear and anger did not predict discriminatory behaviours.The results are discussed in relation to the core values of social work and to professional identity.