Dr. Joaquin Barnoya joined the University of California, San Francisco (UCSF) as a Legacy Foundation fellow at the Center for Tobacco Control Research and Education.

As a researcher, Barnoya made significant contributions to the study of the tobacco industry in Latin America and to the examination of secondhand smoke's impact on the cardiovascular system. His analysis was selected by the American Heart Association as one of the top 10 scientific advances of 2005.

In 2011, he was awarded by The Academy of Sciences for the Developing World (TWAS) for his work on controlling chronic diseases caused by tobacco, as well as congenital diseases in children. Five years later, he received the Distinguished Faculty Award from Washington University in St. Louis.

He served as Director of Research at the Cardiovascular Surgery Unit (UNICAR) in Guatemala.

He is an Associate Researcher at Rafael Landívar University (URL) and Director of Research at the Integra Oncology Institute of Guatemala. Additionally, he is a member of the Latin America Advisory Council of the British Medical Journal.

From 2016 to 2018, he was an Associate Professor of Surgery at the Washington University School of Medicine.

Since 2022, he has been an Assistant Professor at the University of Colorado Denver, in the Colorado School of Public Health, Department of Occupational and Environmental Health.

As a researcher, he has authored 101 publications in indexed journals and eight invited publications.