peer reviewed ; The Red Kite Milvus milvus is a raptor which been classified as "near threatened" in the IUCN red list due to rapid decline of several breeding population at the end of the 20th century. Curiously, in Belgium, the small but increasing breeding population did not experience these recent declines. The aim of this work is to contribute to the understanding of the drivers responsible for the Red Kite population favourable status in the eastern Belgian districts. It is devoted, firtly, to the study of the Red Kite diet during its breeding period, by analysing the pellets contents and the prey remains found in and around 176 Red Kite nests and, on the other hand, to the study of the potential association between diet and the reproductive success of pairs.The most consumed prey categories are equally mammals (mainly composed of voles) and young birds. In particular, the water vole Arvicola terrestris seems to be the most consumed species, followed by the Fieldfare Turdus pilaris. Of all the diet and environmental variables studied, the most important factor explaining reproductive success is the presence of the water vole in the diet. Early mowing of meadows, average temperatures and the number of rainy days are three secondary factors that seem to a significant impact on the breeding success of eastern Belgian Red Kites. However, these three variables are correlated; their impact on the number of young nestlings produced per nest could not be separated.