The atherosclerotic lesion is a site of local production of the lipid-derived inflammatory mediators known as leukotrienes. This production leads to autocrine and paracrine activation of leukotriene receptors of the BLT and CysLT receptor subtypes expressed on leukocytes and structural cells within the vascular wall. Studies in mice, rats, and rabbits have revealed a key role for leukotriene signaling in atherosclerosis, abdominal aneurysms, and intimal hyperplasia. In addition, a major atherosclerotic immune activation may be leukotriene-dependent through mediation of leukocyte cross-talk within the atherosclerotic lesion. Furthermore, leukotrienes induce endothelium-dependent and independent vascular responses. Finally, recent findings indicate that leukotriene-dependent degradation of the extracellular matrix may link this pathway to atherosclerotic plaque instability. Taken together, the leukotriene pathway may represent a putative therapeutic target in the treatment of atherosclerotic vessel disease.