Abstract Background: Carers and families have a key role in supporting adults with intellectual disabilities to make lifestyle behaviour changes. This study explores paid and family carers’ motivation to support change and their attributions around physical activity choices in the individuals that they support. Methods: A between subjects questionnaire design, using two questionnaires adapted specifically for this study, was used to investigate carers’ motivation to support behaviour change and explore how this related to their attributions of physical activity choices. The influence of gender, age and level of intellectual disabilities of the individual that the carer supports were examined. Results: 18 carers participated in the study. There was evidence to suggest that carers’ motivation to support change and attributions were correlated. In addition, motivation and attributions were related to age and level of intellectual disabilities of the individual supported by the carer. Conclusion: Carer attributions might present a barrier to motivation to support change. This may indicate a training need for carers. Further research is required to further explore carer attributions and to further examine the utility of the questionnaire measures adapted for this study.