Sonic hedgehog (Shh) is a key signal regulatory factor in embryonic development. It is reported that Shh signaling plays important roles in prostatic duct differentiation and matrix-epithelium interaction, and thus regulates the development, growth and cell proliferation of the prostate. A disorder in Shh signaling will lead to the production and proliferation of tumor cells. An exploration into the mechanism of Shh signaling in the normal growth and diseased condition of the prostate will offer some significant ideas for the studies on the pathogenesy of prostate diseases.