Background and aim Acute coronary syndrome (ACS) is caused by destabilization and rupture of atherosclerotic plaque in the epicardial coronary artery. Mechanisms that affect cell signaling and production of factors promoting inflammation play the main role in that process. The majority of cellular communication takes place on the membrane whose surface is covered with oligosaccharide structures that are related to membrane proteins and lipids in the form of glycoproteins and glycolipids. Glycosylation is the only modification of proteins and lipid which can result in significant structural changes in the protein, and it is known to play an important role in the integration of different functions in higher organisms. The aim of this study was to determine the genetic expression of glycosyltransferases in patients with acute coronary syndrome and compare it with a control group of subjects that are proven to be coronary disease free. ----- Subjects and Methods The study included 52 patients with acute coronary syndrome and 32 subjects in the control group. Glycosyltransferases genetic expression was measured in patients with ACS on two occasions: in the acute phase within 24 hours of acute onset of chest pain, and in chronic phase (average of 8 days after onset of illness). After reverse transcription of RNA into DNA, real-time PCR was performed by SYBR Green protocol, and relative expression was measured. Reference genes used for relative expression measurement were β-actin and GAPDH. Statistical analysis was done using Mann-Whitney test, Wilxocon signed rank test, Spearman correlation test and chi square test. The level of significance was set to P<0.05. ----- Results There was a significantly lower relative expression of FUT 4 in patients with ACS in relation to both reference genes (P <0.001 for GAPDH and P <0.05 for beta-actin). This significant difference was also reflected in the second sampling in patients with ACS. There was no significant difference in FUT 7 expression between two groups in the acute phase. However, due to an almost 50% reduction in the expression of FUT 7 in patients with ACS in the second sampling, FUT7 expression in the second sampling was significantly lower when compared with the control group (P <0.001 for both reference genes). This effect was attributed to statin therapy, as significant downregulation of FUT 7 was found in subjects taking statins irrespective of the presence of acute coronary syndrome. ST6Gal1, GM3 synthase and ST6GalNac 4 were significantly downregulated in patients with ACS in both stages of disease (P <0.05, P <0.001 and P <0.05, respectively). There was a significantly lower expression ST6GalNac3 in ACS patients in the second sampling, which was also attributed to a significantly higher prevalence of statin therapy. ----- Conclusion There were significant differences in gene expression of glycosyltransferases responsible for the synthesis of lectins, syalizated Lewis X antigen, and ganglioside and for integrins syalization. All these structures play an important role in the promotion and control of inflammatory response, which is important in the development and progression of atherosclerosis. More basic and clinical studies on glycosyltransferases and glycosilation in the pathophysiology of the ACS are mandatory.