Bone morphogenetic proteins (Bmps) are phylogenetically conserved signaling molecules that belong to the transforming growth factor beta superfamily. Although these proteins were first identified because of their ability to induce ectopic bone and cartilage formation, they are also involved in the cascades of body patterning and morphogenesis. Recently, several reports have indicated that the administration of pharmacological doses of Bmps inhibits and repairs acute and chronic renal injury in animal models. However, its mechanism of action and physiological function are not well understood. In addition, the exogenous administration of Bmps causes undesired side effects in other tissues, because Bmp receptors are widely expressed. The activities of Bmps are regulated by Bmp antagonists, which bind directly to Bmp and inhibit its binding to the receptor. Thus, the Bmp antagonists that modulate endogenous Bmp activities may be possible new therapeutic targets for kidney disease. In this review, we discuss recent findings related to Bmp antagonists modifying the function of Bmps in kidney disease.