Objective The primary objective of this study was to provide an initial test of the efficacy of acceptance‐based behavioural therapy in reducing pathological worry and anxious symptomology in children. A secondary objective was to examine the benefit of supplementing standard acceptance‐based behavioural therapy with a multisensory learning aide (MSA). The MSA provides kinaesthetic, tactile, and visual stimuli to facilitate children's understanding of acceptance‐based behavioural therapy principles and the development of acceptance‐ and mindfulness‐based skills. Method Two variations of an acceptance‐based behavioural therapy treatment were administered over 8 weeks to children aged 7–11 years: a standard acceptance‐based behavioural therapy treatment condition, and a condition that supplemented acceptance‐based behavioural therapy with a novel MSA. Anxious symptomology and pathological worry were measured at pre‐treatment and post‐treatment. A program evaluation questionnaire was also administered to parents at post‐treatment. Results Results demonstrated that children in the acceptance‐based behavioural therapy with a novel MSA condition reported significant reductions in worry and anxious symptomology at post‐treatment. Furthermore, parents in this condition reported the model to be effective in helping their children understand concepts of acceptance, defusion, and meta‐cognition. Conclusions The present study found that acceptance‐based behavioural therapy, adapted for children and supplemented with a novel multisensory aide designed specifically to enhance treatment, led to reductions in child‐reported worry and parent‐reported anxiety. Parental feedback suggested that the multisensory aide was highly acceptable, and that it may have facilitated children's understanding of abstract therapeutic principles.