Objectives: To draw advocacy lessons from actions undertaken by public health groups to assist the development of Australia and New Zealand's Health Star Rating (HSR) front-of-pack nutrition labelling system. Methods: The advocacy approaches undertaken by the Public Health Association of Australia leading up to the time of the adoption of the HSR is examined using a 10 step advocacy framework. Key roles in advocacy planning and implementation are described, along with coordinating efforts by health and consumer groups during the HSR development processes. Results: HSR aims to support consumers to make informed choices to protect from diet-related diseases, including obesity. The HSR launched despite a number of major obstacles, owing to a strategic, coordinated advocacy effort undertaken by a guiding coalition. Conclusions: Actions to improve nutrition are often highly contested, particularly if the desired outcome competes with commercial interests. However, by deploying a structured approach to public health advocacy it is possible to influence government despite opposition from commercial interests. Implications for public health: A shared vision and a coordinated effort by public health professionals enabled advocates to overcome undue commercial influence.