Objective: Nut consumption has beneficial effects on protection for development of atherosclerotic process. Materials and Methods: Single intervention study design was used to determine the effects of hazelnut-enriched diet (1 g/kg/day) during 4 weeks period on atherogenic tendency of low-density lipoprotein (LDL) by evaluating susceptibility of LDL to oxidation, α-tocopherol content of LDL, LDL subfractions, plasma oxidized (ox) LDL, lipid and lipoprotein levels in normolipidemic healthy subjects (n=21). Statistical analysis was performed using paired t test, ANOVA for repeated measurements test, Pearson’s and Spearman correlation analyses. Results: Lag time for oxidation (baseline 54.6±12.3 min, 15th day 59.3±13.4 min, 30th day 65.2±17.8 min, p=0.001) and α-tocopherol content of LDL (baseline 4.82±1.2 μg/mg LDL protein, 15th day 4.88±1.4 μg/mg LDL protein, 30th day 5.35±1.7 μg/mg LDL protein, p=0.02) were found to be increased while ox-LDL levels (baseline 57.2±16.2 U/L, 15th day 51.2±13.6 U/L, 30th day 48.2±14.2 U/L, p=0.001) decreased during the study period. Total cholesterol, LDL-cholesterol, apolipoprotein (apo) B and apo B/apo AI ratio were found to be significantly lower while apo AI was higher (p<0.05). In respect to LDL subfraction, ratio of large/small LDL was significantly increased at the end of the study (baseline 3.79±1.35, 15th day 3.41±1.60, 30th day 4.28±2.44, p= 0.046). Conclusion: Hazelnut-enriched diet may play important role in decrease in atherogenic tendency of LDL by lowering the susceptibility of LDL to oxidation and plasma ox-LDL levels, and increasing the ratio of large/small LDL beyond its beneficial effect on lipid and lipoprotein levels.