After the Fukushima Daiichi nuclear power plant accident, the internal and external exposures of the residents have been very important issues and concerns. Fukushima prefectural government and Fukushima medical university have been performing the Fukushima Health Management Survey, and the external exposures of the residents have been estimated in the survey by using NIRS external dose estimation system. The doses of 66.3% residents were >1 mSv, and 94.8 % were >2 mSv. For estimating internal exposures of the residents, thyroid measurements, whole body counter measurements and simulation have been applied. These three approach estimations showed that the 90 percentile of thyroid equivalent doses were 10–30 mSv for 1-year-old baby and were 10–20 mSv or less for adults.