The aim of this research was to study roles, strengths and challenges of robot-mediated interventions using robot KASPAR for children with autism spectrum disorder (ASD). Twelve focus group sessions were organized in which 70 ASD care and/or education professionals participated. Six roles for KASPAR were identified: provoker, reinforcer, trainer, mediator, prompter, and diagnostic information provider. Strengths of KASPAR are related to personalisation possibilities, its playfulness, the action-reaction principle, its neutral expression, consistent and repetitive application of actions, possibilities to vary behaviour in a controlled manner and having an extra hand. Challenges of working with KASPAR were: limited reaction possibilities, possibility of children being scared of KASPAR, difficulties with generalisation or transfer and finally potential dependence on KASPAR.