Manuel Otero has a master's of science in agricultural development from the University of London, a master's in animal science from the Tropical Agricultural Research and Higher Education Center (CATIE) headquartered in Costa Rica, and is a qualified veterinarian from the Faculty of Veterinary Sciences at the University of Buenos Aires. He began his career at Inter-American Institute for Cooperation on Agriculture (IICA) in 1988 at its headquarters. He has worked as an advisor to the director general, as director of programming and evaluation, as director of the Andean Regional Centre, and as IICA representative to Uruguay and to Brazil.

He has authored several technical documents on international trade, sectoral policies, and agricultural modernization. Previously, he served in Washington, DC as an agricultural attaché for Argentina's Ministry of Agriculture. He was also vice president of Argentina’s National Institute of Agricultural Technology (INTA). He was elected in 2017 as director general of the IICA for the 2018–2022 period. In his first few months in office, Otero focused on laying the foundation for the transformation of the institute, the primary mission of which is to promote agricultural and rural development in its 34 member states through technical cooperation of excellence. With this objective in mind, he has succeeded in implementing an innovative policy on partnerships, by developing work agendas with multilateral, bilateral, national, and local entities and with the private sector, with a view to strengthening agriculture, rural well-being in the Americas and the fulfillment of the UN sustainable development goals (SDGs), based on new models of cooperation. In keeping with his demonstrable leadership role in the western hemisphere, the 2021 UN Food Systems Summit nominated Otero to be a member of the Multi-Actor Food Systems Champions Network to represent the agricultural and rural sectors of North America, Latin America, and the Caribbean. As a champion, he is committed to providing effective advocacy for improved resilience and sustainability in the agricultural sector of the Americas.