FGF9 has complex and important roles in skeletal development and repair. We have previously observed that Fgf9 expression in osteoblasts (OBs) is regulated by G protein signaling and therefore the present study was done to determine whether OB-derived FGF9 was important in skeletal homeostasis. To directly test this idea, we deleted functional expression of Fgf9 gene in OBs using a 2.3 kb collagen type I promoter-driven Cre transgenic mouse line (Fgf9OB−/−). Both Fgf9 knockout (Fgf9OB−/−) and the Fgf9 floxed littermates (Fgf9fl/fl) mice were fully backcrossed and maintained in an FBV/N background.