Experience shows that the implementation of sustainability programs can be problematic, particularly for small businesses that dominate sectors such as tourism. A cluster approach can provide a clearer path to sustainability while also offering support and savings on resources and cost. This paper investigates learnings emerging from EC3 Global's voluntary business sustainability program, which was implemented with six tourism clusters involving 307 businesses in Australia in 2008e2010. Founded by Australia's Sustainable Tourism Cooperative Research Centre, EC3 Global is an international tourism and environmental management and advisory group that offer sustainability solutions for enterprises, destinations, and communities. Results provide insight into the lessons offered by the implementation of a tourism business sustainability cluster program, including the need for cluster champions and building ownership at the grassroots level. Importantly, this research supports the premise that individuals, businesses, and clusters can 'make a difference' and postulates a multi-level interaction cluster theory that harnesses learning, both internally and externally to the cluster.