Updated project metadata. Endothelial cells (ECs) line the inner wall of blood vessels and maintain vascular stability. Vascular stability alteration is a hallmark of pathologies such as cancer and thrombosis. A role for fatty acid oxidation (FAO) in this process is unknown. Integrating MS-proteomics and metabolic modeling revealed that FAO increases when ECs cultured on matrigel are assembled into a fully formed network. Inhibition of CPT1A in ECs, a limiting enzyme in FAO, results in disruption of this network. Acute CPT1A inhibition reduces cellular ATP levels and oxygen consumption, which can be restored replenishing the tricarboxylic acid cycle (TCAc). Phosphoproteomic changes upon acute CPT1A inhibition evoked those triggered by thrombin, a potent inducer of EC permeability through calcium signaling. Indeed, CPT1A inhibition increased EC permeability and vascular leakage, which were restored replenishing the TCAc or, partially, inhibiting calcium influx. Our study shows the possibility of altering FAO to interfere with ECs in diseases.