Objective The present paper describes a model for public health nutrition practice designed to facilitate practice improvement and provide a step-wise approach to assist with workforce development. Design The bi-cycle model for public health nutrition practice has been developed based on existing cyclical models for intervention management but modified to integrate discrete capacity-building practices. Setting Education and practice settings. Subjects This model will have applications for educators and practitioners. Results Modifications to existing models have been informed by the authors' observations and experiences as practitioners and educators, and reflect a conceptual framework with applications in workforce development and practice improvement. From a workforce development and educational perspective, the model is designed to reflect adult learning principles, exposing students to experiential, problem-solving and practical learning experiences that reflect the realities of work as a public health nutritionist. In doing so, it assists the development of competency beyond knowing to knowing how, showing how and doing. This progression of learning from knowledge to performance is critical to effective competency development for effective practice. Conclusions Public health nutrition practice is dynamic and varied, and models need to be adaptable and applicable to practice context to have utility. The paper serves to stimulate debate in the public health nutrition community, to encourage critical feedback about the validity, applicability and utility of this model in different practice contexts.