The secretariat has been based in Vienna, Austria and is provided by the United Nations Environment Programme (UNEP) since 1976. The Secretariat organizes and services the annual sessions of the Scientific Committee and manages the preparation of documents for the Committee's scrutiny.

Mr Tiberio Cabianca is a physicist by training, holding an MSc in Radiation Physic from University College London. He has more than 30 years of technical expertise in radiation science and protection, particularly in the area of assessment of radiological consequences from radioactivity in the environment. He spent most of his career at the National Radiological Protection Board (now UK Health Security Agency) in the UK; between 1999 and 2005 he was a staff member with the Nuclear Safety Department of the International Atomic Energy Agency.

Mr Ferid Shannoun is a medical physicist by training, holding a PhD in Public Health and two master’s degrees from German Universities. Since August 2021, he is the Deputy Secretary and Senior Scientific Officer of the UNSCEAR secretariat, which he joined as Scientific Officer in March 2011. He has 25 years of technical expertise in radiation science and protection, including four years with the World Health Organization (WHO), where he worked as Scientist at the Department of Public Health and Environment and nine years as Medical Physics Expert at the Radiation Protection Department of the Ministry of Health in Luxembourg. From December 2023 to March 2026 he served as scientist at WHO on secondment.
Former Secretaries of UNSCEAR were: