Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are not only byproducts of normal cellular metabolism, but also play important roles in cell signaling. However, when the levels of ROS and RNS increase, cells are exposed to oxidative stresses, which activate a variety of mechanisms to allow them to cope with these changes. Studies have shown that oxidative stress conditions play an important role in both the initiation and the progression of prostate cancer by regulating molecules such as DNA, enhancers, transcription factors, and cell cycle regulators. Other studies have shown that antioxidants, molecules that protect cells against oxidative stress, play a role in prevention of prostate cancer. This review summarizes the effects of oxidative stress on the development of prostate cancer and explores the potential of ROS regulators as preventatives for prostate cancer.