Many studies have reported population declines and range contractions of bird species in agricultural landscapes around the world. However, few studies have described population trends of bird species in rice-paddy areas or identified causes of decline in these areas as opposed to other types of farmland. The Greater Painted Snipe Rostratula benghalensis is strongly dependent on rice-paddy areas for habitat. This paper uses the results of local field surveys and national survey data to document the population trends of Greater Painted Snipe in Japan. Field surveys conducted in Ibaraki Prefecture indicated a severe decline over a recent 10-year period. Data from the National Surveys on the Natural Environment also showed that the distribution of the Greater Painted Snipe has decreased nationwide from the 1970s to the 1990s. This population decline might be due to (1) the introduction of an efficient drainage system in rice fields and/or (2) a reduction in the area of flooded fallow fields with short vegetation at both breeding and wintering sites. Further work on the conservation status of this species is urgently needed.