The Directory of Open Access Journals is nowadays the largest database of reliable, peer-reviewed, and completely open access journals, curated by the community. DOAJ covers all areas of science, technology, medicine, social science and humanities and includes journals from 135 countries. More than 10,000 journals have been indexed in DOAJ since its creation in 2003, but as a way of keeping the database as reliable and useful as possible, in 2014 DOAJ has implemented some new criteria that aim to improve quality and transparency in indexed journals. The criteria is based in Principles of Transparency and Best Practice in Scholarly Publishing, established by DOAJ in collaboration with other Open Access initiatives, such as the Open Access Scholarly Publishers Association (OASPA). Thanks to a grant from the International Development Research Centre (IDRC) to improve open access publishing practices in the Global South, 15 ambassadors were hired to promote transparency and best practice in order to make journals an attractive channel to communicate science in the increasing market of scholarly publishing. These 15 people represent Latin America, Africa, India, China and Russia, where open access is becoming the predominant publishing model. The team work that has been done shows that Open Access is not only a way of giving public access to scientific information, but a philosophy of sharing knowledge and strengthen links between regions that benefit science diffusion. This paper presents some of the achievements of DOAJ in Latin America, emphasizing the advantages of collaboration between different information systems, publishers, institutions and stakeholders in the region that have increased thanks to this DOAJ ambassadors program.