The continuous production of oxidative stress by reactive oxygen species (ROS) is related to the pathogenesis of cardiovascular diseases. The major enzymatic sources of ROS in the cardiovascular system are reduced nicotinamide adenine dinucleotide phosphate oxidase (NOX), uncoupled endothelial nitric oxide synthase, mitochondria, and xanthine oxidases. This article reviews the role of the relationship between these oxidases in cardiovascular diseases, focusing on the core role of specific subtypes of NOX that are activated in different cardiovascular diseases. An improved understanding of these mechanisms can facilitate the development of novel therapeutic agents targeting these oxidase stress-related enzyme systems and their interactions, which will be effective in the prevention and treatment of cardiovascular diseases.