Abstract Background Interventions to reduce population salt intake are feasible and cost-effective. The Victorian Salt Reduction Partnership implemented a complex, multi-faceted salt reduction intervention between 2014 and 2020 in the Australian state of Victoria. This study aimed to understand stakeholder perspectives on the effectiveness of the Victorian Salt Reduction Partnership. Methods Semi-structured interviews were conducted with Partnership and food industry stakeholders. The Consolidated Framework for Implementation Research was adapted for the Partnership intervention and used to guide the qualitative analysis. Results Fourteen Partnership and seven food industry stakeholders were interviewed. The Partnership was viewed as essential for intervention planning and decision-making and an enabler for intervention delivery. The goals of capacity building and collaborative action were perceived to have been achieved. The implementation team executed intended intervention activities and outputs, with some adaptations to strategy. Barriers and enablers to implementation were identified by interviewees, such as compatibility of individual, organisational and Partnership values and building positive relationships between the Partnership and food industry, respectively. Legal, political, social, environmental, technological and economic factors affecting intervention design, delivery and outcomes were identified. Conclusions Establishing a Partnership with diverse skills and experience facilitated collaborative action, capacity building and execution of the intervention. Monitoring and evaluating implementation informed strategy adaptations, which allowed optimisation of Partnership strategy. The importance of developing strong communication networks between strategic and implementation-levels was a key lesson.