Introduction: Atherosclerosis is driven by chronic inflammation of the artery wall in response to cholesterol accumulation and defects in reverse cholesterol transport (RCT). Activation of the NLRP3 inflammasome in foam cells leads to cleavage of Gasdermin D (GsdmD), facilitating release of the mature interleukin-1beta (IL-1β). Work from our lab and others have shown that GsdmD promotes atherosclerosis. Recently, the FDA-approved drug, Disulfiram, was shown to inhibit GsdmD. Though the GsdmD/IL-1β pathway has been implicated in CVD, the efficacy of Disulfiram as an anti-atherosclerotic therapy has not been explored. Hypothesis: We aim to establish a mechanism-based role of Disulfiram as an atherosclerotic therapeutic. We hypothesize that Disulfiram inhibition of GsdmD-pore formation and subsequent IL-1β release will reduce atherosclerosis. Methods and Results: Efficacy of Disulfiram (DSF) as an GsdmD inhibitor was confirmed in inflammasome-induced macrophages and in mice, with both showing significantly reduced IL-1b release with no effect on expression of inflammasome components. To test if DSF can reduce atherosclerosis, hyperlipidemic apoE -/- mice were weaned onto a western-type diet (WTD) or WTD + 25mg/kg DSF for 15 weeks. Excitingly, DSF vs. WTD-fed mice showed smaller lesion burden (p<0.01) by 26.7% for males and 29.4% for females. Total cholesterol levels were higher in DSF vs WTD males (p<0.05) and females (p<0.01). DSF-diet did not impact body or liver weight, white blood cells, platelets, lymphocytes, monocytes or eosinophils. Red blood cells (RBCs) and neutrophils were decreased in females (p<0.01 and p<0.05, respectively), but not in males. DSF-fed mice have reduced macrophage infiltration into atherosclerotic lesion sites. Conclusions: Our pre-clinical data suggests Disulfiram has the potential to be used as a stand-alone therapy or in combination with current atherosclerosis therapies.