Professor Naiyyum Choudhury held many important positions in the Bangladesh Atomic Energy Commission prior to becoming its Member and then Chairman. He was the National Coordinator for Regional Cooperative Agreement (RCA) of the IAEA for Research was elected as its Chairman in the 30th General Conference of the RCA held in Vienna on 15 - 16 September 2000 for two years. He became a member of the New York Academy of Science and British Society for Applied Bacteriology in 1989. He was the President of a number of scientific professional bodies which include Bangladesh Association of Scientists and Scientific Professions (BASSP); Bangladesh Biochemical Society, Bangladesh Tissue Banking Association, Bangladesh Society of Microbiologists (BSM) and Bangladesh JSPS Alumni Association. He was actively involved in development of a concept paper for a Biotechnology Institute and was the founder Project Director of the National Institute of Biotechnology (NIB). He was involved in drafting the National Bio-safety Guidelines in 1999 and then in 2005 and now and he is a member of the Biosafety Core Committee (BCC) of the government. He was the Convener of the Committee for formulation of the National Biotechnology Policy 2005, National Science and Technology Policy, 2011 of the Bangladesh Government and is Advisor of the Committee on formulation of the Action Plan of the Policy. He is a Member of the Executive Committee of the National Council for Science and Technology (ECNCST).
Professor Choudhury has been involved in teaching since 1982 and taught in different universities of Bangladesh. At the time of his death he was serving as the Vice President of the Bangladesh Academy of Sciences, Chairman of the Bangladesh Atomic Energy Regulatory Authority (BAERA).