Multimodality MRI including DCE-MRI and DW-MRI were performed in patients prior to and following hypofractionated stereotactic body radiotherapy (SBRT). Diffusion and perfusion related parameters in both tumor and non-tumor benign tissue were calculated at 3, 6, and 12 months after SBRT. Radiation-induced changes were observed in perfusion and diffusion related parameters in tumors. In the non-tumor transition zone, SBRT induced changes in perfusion-related parameters. Multimodality MRI has potential for treatment effect monitoring in the prostate after SBRT.