Background and Objective:Recent studies have shown that not only the quantity, but also the quality of dietary fatty acids can affect lipid parameters. Elaidic acid is a major hydrogenated by-product of vegetable oil play a role in the development of cardiovascular disease, especially atherosclerosis, through changing lipid profile and increase in inflammation and inflammatory factors. On the other hand, the role of TNF-α is evident in inflammatory pathways and inflammation outcomes, which are involved in the initiation of atherosclerosis. Therefore, in the current study the effect of elaidic acid on TNF-α gene expression, was investigated.Methods: RAW264.7 cells were treated with 100 and 200 μM of elaidic acid for 12 h. Then, expression of TNF-α gene was assessed after RNA extraction and cDNA synthesis.Result: TNF-α gene expression in RAW264.7 macrophage cell line showed no significant difference for both concentrations compared to the control.Conclusion: These results indicated that elaidic acid affect the development and acceleration of atherosclerosis in other ways than through TNF-α nuclear receptor.