The Brazilian Strategy for the Prevention and Care of Childhood Obesity (PROTEJA) aims to implement a set of actions to prevent obesity in Brazil. As such, this qualitative and descriptive documentary study presents the Strategy’s stages of the operational design, general proposal, evaluation and monitoring conducted by the Brazilian Ministry of Health’s technical coordination. After analyzing the epidemiological data on children and the existing policies aimed at obesity prevention, and reviewing the scientific literature and recommendations, PROTEJA was formulated and approved by the Brazilian Ministry of Health, and 1,320 municipalities committed to implementing 20 essential and 5 complementary actions, from 41, including some structural to improve environments. Coordinated by the Brazilian Ministry of Health in partnership with subnational governments and universities, the Strategy also relies on a local team for implementation support, as well as implementation and impact evaluations. Actions will be monitored annually, and the indicators will impact financial incentives. As a strong, evidence-based and innovative strategy aiming to promote healthy environments in cities, PROTEJA has the potential to open a path to childhood obesity reversal, as well as add to the implementation science and contribute to the development and improvement of public policies for obesity prevention; however, its implementation remains a challenge.