Growth differentiation factor 11 (GDF11), also known as bone morphogenetic protein 11 (BMP11), is a member of the transforming growth factor β (TGF-β) superfamily. Although GDF11 plays pivotal roles during development, including anterior/posterior patterning, formation of the kidney, stomach, spleen and endocrine pancreas, little information is available for GDF11 expression in the adult central nervous system (CNS). We, thus, investigated GDF11 expression in the adult rat CNS using immunohistochemistry. GDF11 was intensely expressed in most neurons and their axons. Furthermore, we found that astrocytes and ependymal cells also express GDF11 protein. These data indicate that GDF11 is widely expressed throughout the adult CNS, and its abundant expression in the adult brain strongly supports the idea that GDF11 plays important roles in the adult brain.