This 26th Annual Report of the International System on Occupational Exposure (ISOE) Programme presents the status of the Programme in 2016. As of 31 December 2016, the ISOE programme included 74 participating utilities in 28 countries (343 operating units; 53 shutdown units; 7 units under construction), as well as the regulatory authorities in 26 countries. The ISOE database includes occupational exposure information for over 400 units, covering over 85% of the world’s operating commercial power reactors. This report includes a global occupational exposure data and analysis collected and accomplished in 2016, information on the programme events and achievements as well as principal events in participating countries.