This is a special issue of selected papers from the Third Asian and Oceanic Congress on Radiation Protection (AOCRP-3), which is a congress on radiation protection held every 4 y under the auspices of the Asian and Oceanic Association for Radiation Protection (AOARP). The AOARP is a regional association of International Radiation Protection Association (IRPA). The AOCRP Congress is also a regional congress of IRPA, and has a history of being held in Seoul, Korea (AOCRP-1, 2002) and in Beijing, China (AOCRP-2, 2006). AOCRP-3 was held, in May 24–28 2010, in Tokyo, Japan, and had a lot of participation from more than 30 nations, and almost 500 attendants. The congress covers the following fields: (1) radon, (2) health effects of ionising radiation, (3) radiation measurement, (4) radioactive waste management, (5) emergency preparedness and response, (6) standard, criteria and regulation, (7) NORM/TENORM, (8) exposure to medical radiation, (9) radiological protection, (10) environmental radioactivity, (11) radiation control and management and (12) dosimetry. We would like to present the selected papers to show the remarkable progress in activity of radiation protection in Asia and Oceania. We sincerely hope that this issue will be a source book of our research activity.