Abstract Background Saffron, the dried stigma of the flower Crocus sativus L., has been shown to have therapeutic effects on cardiovascular diseases. Several studies have explored the impact of saffron on atherosclerosis. However, the mechanism underlying the plaque-stabilizing and antiatherosclerotic effects of saffron has not been widely studied. Therefore, this study aimed to investigate the mechanism of the antiatherosclerotic and plaque-stabilizing effects of saffron ethanolic extract in experimentally induced atherosclerotic rabbits. Methods New Zealand White rabbits were fed a 1% high-cholesterol diet (HCD) for 8 weeks to induce established atherosclerosis. The rabbits were then treated with 50 or 100 mg/kg/day saffron ethanolic extract (SAF), simvastatin (2.5 mg/kg/day) or placebo for another 8 weeks. Body weight, lipid profile, percentage of atherosclerotic lesions, immunohistochemical analysis, and quantitative real-time polymerase chain reaction were performed at baseline, after high-cholesterol diet feeding, and after the intervention. Results The results showed that SAF had no significant effect on body weight. However, treatment with both doses of SAF markedly attenuated the levels of low-density lipoprotein (LDL) and total cholesterol (TC) in atherosclerotic rabbits. Higher doses of SAF markedly reduced atherosclerotic lesions in rabbit aortas. Additionally, SAF suppressed the tissue and gene expression of adhesion molecules and pro-inflammatory biomarkers in the aorta. SAF also reduced MMP-9 tissue expression in the aortas of atherosclerotic rabbits, thereby increasing plaque stability. Conclusions Our findings suggest that saffron ethanolic extract exhibits therapeutic potential in rabbits with HCD-induced atherosclerosis. This effect may be associated with the modulation of inflammatory pathways, leading to reduced expression of pro-inflammatory cytokines, endothelial activation markers, and matrix metalloproteinases. The observed reduction in vascular inflammation and endothelial activation may contribute to improved lipid profiles, decreased atherosclerotic lesion severity, and enhanced plaque stability. While these findings highlight the potential of saffron ethanolic extract as an adjunctive treatment for atherosclerosis, further studies are warranted to clarify its direct effects on lipid metabolism and underlying molecular mechanisms. Clinical trial number Not applicable.