The Tokyo Electric Power Company (TEPCO) Fukushima Daiichi nuclear power plant accident caused by the Great East Japan Earthquake on March 11, 2011, resulted in the release of large amounts of radioactive materials (mainly radioactive iodine ¹³¹I, and radioactive cesium ¹³⁴Cs and ¹³⁷Cs) into the environment that subsequently contaminated agricultural products. Currently, agricultural contamination by radioactive iodine, with a short half-life of 8d, is no longer an issue, since three-and-a-half years have passed since the accident. However, the radioactive cesium isotopes ¹³⁴Cs and ¹³⁷Cs have long half-lives (2 years and 30 years), and have maintained 30% and 92% of their initial radioactivity, respectively. Therefore, long-term monitoring of these radionuclides is required with respect to food contamination. Consumers and food manufacturers alike are greatly concerned with the behavior of radioactive materials during the food processing and cooking of raw agricultural materials. Under a wide range of countermeasures to mitigate the consequences of the nuclear accident for agriculture in the affected regions of Japan, the contamination of agricultural products with radioactive cesium has been greatly reduced in the past three-and-a-half years. Furthermore, numerous studies have focused on examining the behavior of radioactive cesium during the processing and cooking of domestic agricultural, livestock, and fishery products. In this paper, we provide an overview of the inspection results of FY2011 to FY2013 on radioactive cesium levels in agricultural, livestock, and fishery products, as well as research results collected to date on radioactive cesium behavior in the processing and cooking of these products. An English version of all figures and tables in this paper is presented in the Appendix.