BACKGROUND/AIM: The use of support workers such as occupational therapy assistants is emerging as a strategy to enhance the health workforce, but there has been little evaluation of the feasibility of expanding support worker roles and responsibilities. This study aimed to implement an advanced occupational therapy assistant-led groups programme in a subacute aged care rehabilitation setting and to evaluate the impact on the clinical outcomes of group participants. METHOD: A prospective quasi-experimental cohort study was conducted comparing outcomes of 30 patients receiving a groups programme led by an advanced occupational therapy assistant with a historical control group of 40 patients receiving the groups programme led by an occupational therapist. The groups programme comprised up to six groups per week and included meal preparation groups and domestic training groups. Outcomes were Functional Independence Measure scores, Australian Therapy Outcome Measures, discharge destination, length of stay and patient satisfaction. RESULTS: Discharge outcomes of patients participating in the assistant-led groups programme were not significantly different to patients who participated in the therapist-led groups programme. Patient satisfaction levels were not significantly different between groups. CONCLUSION: The introduction of an advanced occupational therapy assistant to replace an occupational therapist in facilitating a groups programme in aged care rehabilitation did not result in a decline in patient outcomes. However, the results should be interpreted tentatively given the study limitations and the advanced skills of the assistant involved. Further more rigorous longer term research with a larger sample is required.