Rice (Oryza sativa) is the main cereal grown in the Republic of Korea and Japan and is planted on 54% and 36% of agricultural lands, respectively. Information on the status of birds that use rice fields in these nations was reviewed. More than 30%, or 135 species of 430 native avian species, excluding 152 accidental visitors, use rice fields. The fields serve primarily as foraging habitat, providing aquatic prey for passage, summer and resident species and residual grains for winter visitors. Some species, such as the Grey-faced Buzzard (Butastur indicus), require a mosaic of rice fields and forests for successful breeding. However, most waterbirds prefer rice fields in wide, open plains rather than narrow rice fields surrounded by forest. At least 32 (24%) of 135 species that use rice fields are designated threatened at the global or national scale, and eleven (22%) of 49 globally threatened species found in Korea and Japan use rice fields. Populations of most granivorous and piscivorous waterbirds such as geese, cranes and herons tend to be stable or increasing. The Baikal Teal (Anas formosa) is an exception. The breeding ranges or populations of some carnivorous and insectivorous birds, such as the Ruddy-breasted Crake (Porzana fusca), Greater Painted Snipe (Rostratula benghalensis) and many shorebirds have shrunk in recent decades. Some agricultural and conservation sectors have succeeded in attracting many waterbirds by flooding fallow fields in the rice-growing season and post-harvest rice fields. Further research on the direct and indirect effects of agricultural practices and conservation measures is needed in Korea and Japan.