ABSTRACT Following the development of a framework of sustainability indicators for the Red de Mercados Agroecológicos de Bogotá Región – RMABR, in 2016, it was identified, that only 56% of its producers were agroecological, while the remaining were mostly in the process of agroecological transition. To address this problem, this Participatory Action Research – PAR was carried out in 2016, which included the design, implementation, and evaluation of a PSG. The methodology was subdivided into five phases: participatory diagnosis, agreement on the same language, design of the Participatory System of Guarantees – PSG, pilot implementation, evaluation, and adjustment. The developed PSG encompasses a structure with a PSG committee and certification visiting teams; a justification, definition, and principles of agroecology; formats for participatory certification, agroecological transition plans, seal, and sanctions. PSG is operating, it is cheaper than the Third Party Certification – TPC, it allows certifying producers giving coherence to markets and confidence to consumers, promotes agroecology in producers and allows them to sell in local markets, and has generated cohesion in the RMABR.