Background: As countries currently face growing malnutrition trends (often with a double burden of malnutrition), data on the nutritional status of the population can provide support to local policies, as well as track progress towards goals, such as the global nutrition targets. Brazil has a national nutritional surveillance system (Sisvan), which provides nutritional status data for municipalities, on all age groups. In an effort to offer a more in-depth analysis of the Sisvan, this study investigated the strengths and limitations of the system regarding the available data on children to explore its contribution to the health information system and policy making potential. Methods: A mixed methods approach was used innovatively, with triangulation of results, to combine quantitative descriptive statistics (to determine national coverage and completeness of nutritional status data among children in the Sisvan between 2008 and 2018), with a qualitative phenomenographic analysis of in-depth interviews with stakeholders involved with the system. Results: Results demonstrated on average an increase in coverage within the system of the nutritional status of children nationally from 14% in 2008 to 35,8% in 2018, with variability in this growth over the different areas of the country. The interviews demonstrated that the Sisvan is a tool to improve health conditions that go beyond nutrition. It has the potential to be integrated in a greater structure of Public Health care. After triangulation of results, there was agreements between the quantitative and qualitative analysis, demonstrating that the surveillance system is embedded in the Primary Health Care strategy, albeit current limitations. Conclusion: The Sisvan has the potential to be an important tool for the monitoring of nutritional targets and provision of information for local and national health and nutrition policies. However, more integration between the several instances involved is still a gap, for a full usage of the system and the generated data.