Prostate cancer is a malignant tumor with insidious onset, and it usually gets into a terminal stage when discovered and has limited therapy measures. Hence, novel and more effective diagnostic and therapeutic approaches of prostate cancer are greatly needed. Exosomes are one subtype of extracellular vesicles (30-100 nm) secreted by various living cells. Tumor-associated exosomes have been identified in various body fluids from cancer patients and playing important roles in promoting tumor growth, invasion, metastasis and drug resistance. Furthermore, exosomes have multiple advantages when applied in cancer therapy, including the ability to overcome natural barriers, intrinsic cell targeting properties and stability in the circulation, which implies an enormous potential for treatment of prostate cancer. In this review, we summarized the characteristics and functions of exosomes, and discussed the potential value of exosomes as biomarkers and therapeutic tools for prostate cancer.