Abstract: Recently, a series of shared molecular pathways have emerged that have in common a significant role in the pathogenesis and progression of both atherosclerosis and cancer. Oxidative stress and the cellular damage that results from it have been implicated in a wide variety of disease processes including atherogenesis and neoplasia. Toxic metabolites produced by cigarette smoking and increased dietary fat intake are implicated in the pathogenesis of both diseases. It has been hypothesized that atherosclerosis may begin when an injury or infection mutates or transforms a single arterial smooth muscle cell in the progenitor of a proliferative clone similar to the most widely held theory of carcinogenesis. Cell proliferation regulatory pathways including genes involved in the G₁S checkpoint (p53, pRb, p15, p16, and cyclins A, D, E, and cdk 2,4) have been associated with plaque progression, stenosis and restenosis after angioplasty as well as in cancer progression. Alterations in cell adhesion molecules (integrins, cadherin‐catenins) have been linked to plaque formation and thrombosis as well as to tumor invasion and metastasis. Altered expression of proteases associated with thrombolysis has been implicated in atherosclerotic plaque expansion and hemorrhage and in the invasion and metastasis of malignancy. Ligand‐growth factor receptor interactions (tyrosine kinases) have been associated with early atherosclerotic lesions as well as cancer development and spread. Nuclear transcription factors such as NFκB have been associated with progression of both diseases. Angiogenesis modulators have recently been linked to plaque expansion and restenosis of atherosclerotic lesions as well as local and metastatic tumor expansion. Common disease treatments, such as the use of growth factor inhibitors and radiation treatment, established anticancer treatments, were recently introduced into atherosclerosis therapeutic strategies to prevent restenosis after angioplasty and endarterectomy. In conclusion, a series of molecular pathways of disease development and progression common to atherosclerosis and cancer support that the world's two most common diseases are far more closely aligned than previously believed and that emerging anti‐inflammatory and antiproliferative therapeutic strategies may ultimately be efficacious in both conditions.