Abstract Feasibility study of a remote radiation monitoring system using an autonomous unmanned helicopter, mounted the CCD cameras, the GPS sensor and a radiation detector, has been carried out as measures in a nuclear emergency and for surveying high radiation area in the environment. This system can fly for the destinations and return by the automatic operation, and the radiation data can be collected during the flight. Radiation data measured are transmitted immediately with image data to the monitoring station on the ground. It is possible to monitor these data on the map of the computer display in the real time. As a result of the flight tests, it is confirmed that the fluctuation of the dose-rate distribution on the ground is measured by this system, and it can be used for the radiation monitoring in case of a nuclear emergency.