ABSTRACT.- Plants grow associated with complex communities of organisms, and their development depends largely on management practices, available nutrients in the soil, environmental conditions, and the balanced equilibrium established among all these factors. In unbalanced environments, diseases, insects, and weeds can decrease agricultural productivity or even destroy crops. There is great interest in developing effective and complementary strategies and approaches to include in the integrated management of phytopathogens and pests, such as the application of formulations containing microorganisms with biological control capabilities. In Uruguay, several groups have been studying microbes that can be used as biological control agents, and there has been a clear interest in the implementation of biocontrol strategies. In this regard, Uruguay has taken several steps towards more sustainable agricultural practices, such as the implementation of a registration procedure for biopesticides and biofertilizers, and the creation of the National Plan for Fostering Agroecological Production. A positive outcome of these actions is the increase from only 2 to 13 registered products in the last 10 years. Registered formulations are based on bacteria, fungi, and viruses, including antagonists of plant diseases and entomopathogens for the control of insect pests. More than half of the registered products contain organisms isolated in Uruguay. Additionally, Uruguay occupies the eighth position in the world ranking of land destined for organic production. This review presents a summary of the history and outcomes of biological control research in Uruguay on beneficial microorganisms (bacteria and fungi) able to antagonise and control phytopathogenic fungi, oomycetes, and insect pests. © The Author(s) under exclusive licence to Society for Environmental Sustainability 2023