Endothelial nitric oxide synthase (eNOS) plays an essential role in the regulation of endothelial function and acts as a master regulator of vascular tone and homeostasis through the generation of the gasotransmitter nitric oxide (NO). The complex network of events mediating efficient NO synthesis is regulated by post-translational modifications and protein-protein interactions. Dysregulation of these mechanisms induces endothelial dysfunction, a term often used to refer to reduced NO bioavailability and consequent alterations in endothelial function, that are a hallmark of many cardiovascular diseases. Endothelial dysfunction is linked to eNOS uncoupling, which consists of a switch from the generation of NO to the generation of superoxide anions and hydrogen peroxide. This review provides an overview of the eNOS signalosome, integrating past and recently described protein-protein interactions that have been shown to play a role in the modulation of eNOS activity with implications for cardiovascular pathophysiology. The mechanisms underlying eNOS uncoupling and clinically relevant strategies that were adopted to influence them are also discussed.