Objective The aim of the present study was to identify areas where allied health assistants (AHAs) are not working to their full scope of practice in order to improve the effectiveness of the allied health workforce. Methods Qualitative data collected via focus groups identified suitable AHA tasks and a quantitative survey with allied health professionals (AHPs) measured the magnitude of work the current AHP workforce spends undertaking these tasks. Results Quantification survey results indicate that Victoria’s AHP workforce spends up to 17% of time undertaking tasks that could be delegated to an AHA who has relevant training and adequate supervision. Over half this time is spent on clinical tasks. Conclusions The skills of AHAs are not being optimally utilised. Significant opportunity exists to reform the current allied health workforce. Such reform should result in increased capacity of the workforce to meet future demands. What is known about the topic? Increasing skill shortages across Australia’s health workforce necessitates that the capabilities of all healthcare team members should be used optimally. AHA roles are an important and growing response to current health workforce needs. Increasing workforce capacity will ensure the right health workers are matched to the right task by skill, experience and expertise. What does this paper add? This paper presents a model that assists services to identify tasks suitable for delegation to an AHA by an AHP. The model is unique because it describes a process that quantifies the need for AHAs and it has been successfully implemented in rural, regional and metropolitan health services in Victoria. What are the implications for practitioners? Working collaboratively, with executive support, will lead to a sustainable and integrated approach to support workforce capacity building. Altering the skill mix of healthcare teams through increasing the role of AHAs has benefits for AHPs, patients and the healthcare system.