BACKGROUND: The level of plasma fibrinogen has emerged as an important risk factor for cardiovascular diseases. Raised fibrinogen levels result in enhanced fibrin deposition in areas of vessel wall injury, which in turn may accelerate the development of atherosclerotic disease. The aim of present study was to investigate whether the plasma fibrinogen levels was related to carotid atherosclerosis in type 2 diabetic patients. METHODS: The sbjects of this study were 210 type 2 diabetic patients. The intima-media thickness (IMT) and plaques in the each segment of the both carotid arteries were evaluated by a duplex scan. The mean of the total IMT values (7 points on each side), the each mean value of the CCA, bulb and ICA, and the maximal IMT, plaque count and score were measured. The plaque score was defined by the sum of longitudinal diameters of each plaque. RESULTS: The correlation between the plasma fibrinogen level and measured IMT values was statistically insignificant (r<0.15, P>0.05). However, there were significant positive correlations between the level of fibrinogen and the plaque count (r=0.20, P=0.019) or plaque score (r=0.24, P=0.006). Stepwise multiple regression analysis revealed the level of plasma fibrinogen as a predictor of the plaque score. CONCLUSION: These results suggest that an elevated plasma fibrinogen level may be related with carotid atherosclerosis in type 2 diabetic patients. Also, there a need to address the discriminating risk factors for the formation or progression of plaques, or IMT thickening.