Bachelor of Medicine and Surgery (MB ChB), Fellow of the Royal College of Physicians of Ireland (FRCPI), Fellow of the Royal College of Physicians of Edinburgh (FRCP Edin) Fellow of The World Academy of Sciences (FTWAS), Fellow of Uganda National Academy of Science (FUNAS),  Fellow of African Academy of Sciences (FAAS) and recipient of 4 Doctor of Science Degrees (DSc hc) from universities in Uganda, Canada and Ireland. 

Prof. Mugyenyi, currently the President of UNAS, is a Paediatrician, researcher and specialist on HIV/AIDS and related conditions. He was the Executive Director of the Joint Clinical Research Centre (JCRC), Kampala (1992-2017) recognized as centre of excellence in medical research, training and healthcare where he established a CAP certified research laboratory that supported many landmark, national, multicenter and international collaborative research including a pioneer HIV vaccine trial in Africa.  He was among the first to introduce the use of anti-retroviral (ARV) therapy in Africa, as well as development of an effective model to effectively scale it up in resource limited countries.
In his long career he has served in various capacities and held important responsibilities in national and international medical, academic and research institutions, a well as government and Non-Governmental Organizations (NGOs). Among them in Uganda include, serving as President: Uganda Pediatric Association, Chairman of Uganda Blood Transfusion Services, Medical Sciences Committee of Uganda National Council of Science and Technology, Uganda Ministry of Health AIDS Task Force and Uganda National Academy of Science Research Committee. At Mbarara University of Science and technology (MUST), he was appointed Visiting  Professor of Medicine, Chairman of University Board and later the Chancellor of the MUST.

Internationally he served as Editor, Journal of the international Association of Physicians in AIDS Care (Washington)   Member of advisory Board of Africa International Scientific Centre - University of KwaZulu Natal, South Africa, Senior Associate HIV/AIDS programs: Management Sciences for Health (MSH),USA,  Member; Public Health and Tropical Medicine Committee Welcome Trust, London,  HIV Vaccine Trial Network (HVTN) Advisory Board, Bethesda USA, Massachusetts General Hospital Center for Global Health Advisory Board, USA,  Board member Medical Research Council (MRC), Global Health Group, London UK, UNAIDS, Member of UNAIDS Scientific and Technical Advisory Committee, (STAC) Geneva. Among the international Consultancy work include, AIDS exploration in Africa-one of the first in-depth study that described the magnitude of the AIDS epidemic. Among others include Consultancy to Haiti, AIDS Control Program, AIDS Control Program of Kenya, and UN Habitat,
Professor Mugyenyi is among those who championed HIV/AIDS prevention, treatment and advocacy. In recognition of his role he was invited to the US Congress during the 2002 State of the Union address when President Bush announced a $15 billion emergency fund to fight the HIV/AIDS crisis in Africa and the Caribbean (also known as PEPFAR).
As a researcher Prof. Mugyenyi has been a Principal Investigator many landmark research projects some of them funded by National Institutes of Health (NIH), European Union, WHO and Medical Research Council (MRC). His research and publications cover a wide spectrum of HIV/AIDS, related diseases and other medical conditions. Specific areas of his research include: paediatric and adult HIV treatment, drug trials, HIV resistance, HIV prevention, immunological studies including HIV vaccine trials, pharmacokinetic, molecular and epidemiological studies as well as social and economic impact of HIV. He is an author of a number of books, book chapters and published over 200 research papers in peer reviewed journals