Despite strong evidence for a relationship between high salt intake and hypertension, plus the widespread recommendations for dietary salt restriction among hypertensive subjects, there are no nursing studies describing effective theory-based interventions. To describe a systematic process for development of a theory-based nursing intervention that is aimed at reducing salt intake among hypertensive women, by applying the intervention mapping protocol. We developed our intervention following the six steps of the intervention mapping protocol: assessing needs, creating a matrix of change objectives, selecting theoretical methods and practical applications, defining the intervention programme, organizing the adoption and implementation plan, and defining the evaluation plan. Addition of salt during cooking is identified as the main source for salt consumption, plus women are identified as the people responsible for cooking meals at home. In our study, the motivational predictors of this behaviour were self-efficacy and habit. Guided practice, verbal persuasion, coping barriers, consciousness-raising and counter-conditioning were the theoretical methods we selected for enhancing self-efficacy and promoting habit change, respectively. Brainstorming, role-playing, cookbook use, measuring spoon use, label reading, hands-on skill-building activities and reinforcement phone calls were the chosen practical applications. We designed our intervention programme, and then organized the adoption and implementation plans. Finally, we generated a plan to evaluate our intervention. Intervention mapping was a feasible methodological framework to guide the development of a theory-based nursing intervention for dietary salt reduction among hypertensive women.