Background: Background: The new Guideline for early detection of breast cancer is the first Brazilian Ministry of Health Guideline based on Systematic Reviews and applies the GRADE System, establishing new standards for guidelines development in the country. The implementation of evidence-based guidelines is a worldwide challenge and traditional strategies based only on the dissemination of their text are proven to be insufficient to generate changes in current clinical practice.

Objectives: To assess barriers that can impact the implementation of current guidelines and strategies for overcoming them

Results and Conclusions: Although these guidelines are based on good-quality evidence, their recommendations are still counter-hegemonic in the international and national arena, both in the common sense, in the mainstream media, among health professionals, academics and managers, as well as explicit rejected by some medical societies and advocacy groups. A major challenge to adherence to the new Guidelines for Early Detection in Brazil is the current pattern of use of mammographic screening in the country, with screening of young women and short interval between examinations. This harmful practice to the health of the population is reinforced by the dissemination of misinformation, which overestimates the benefits of screening and underestimates or even omit its risks, as well as the practice of defensive medicine. To overcome these barriers, changes related to the regulation of care, financing, and the implementation of the shared decision-making process in primary care are essential. Audit-feedback, academic detailing and incorporation of decision aids are some of the strategies that may facilitate the implementation process of the new guidelines in the country.