Oxidative stress is a major contributor to the etiology of all severe vascular pathologies, such as atherosclerosis. NADPH oxidases (Nox) are a class of multicomponent enzymes whose unique function is the generation of reactive oxygen species (ROS) in the vascular cells and in circulating immune cells interacting with blood vessels. Physiological production of Nox-derived ROS contributes to the maintenance of vascular homeostasis. In pathological states, hyperactivity of Nox induces oxidative stress. Nox-derived ROS interact and stimulate other enzymatic sources of oxygen/nitrogen reactive intermediates, and amplify the initial response to insults. In atherosclerosis, Nox-induced lipid peroxidation is highly deleterious and expands the free radical reactions initially produced by activated Nox. Therefore, understanding the molecular mechanisms of Nox regulation, vascular and subcellular compartmentalization of ROS production and its subsequent biological significance, may lead to a focused and effective anti-oxidative stress therapy. We present here, recent advances in Nox regulation in the vasculature and discuss novel potential intrinsic feedback mechanisms and current and pharmacological perspectives to target Nox, which may have an impact in vascular health and disease.