Aim To observe the serum ferritin (SF) expression in cerebral infarction and carotid atherosclerosis. Methods Carotid atherosclerosis of all enrolled patients were evaluated by ultrasonography and the level of SF were detected in blood plasma. The SF content in cerebral infarction group was compared with control group; the relationship between SF and carotid interia-media thickness (IMT)/carotid plaque scores was analysed. Results 77 (70.6%)patients were detected to have carotid atherosclerosis in cerebral infarction group, and 30 (39.5%) patients were detected to have carotid atherosclerosis in control group. The level of SF in cerebral infarction group was higher than that in control group (248.5±107.4 μg/L vs 197.6±94.8 μg/L, p<0.05). Partial correlation analysis of SF and carotid IMT/ plaque scores showed positive correlation, and the partial coefficient were 0.56 and 0.48 respectively (p<0.05). The level of SF was positively correlated with low density lipoprotein in plasma, and the pearson coefficient was 0.51 (p<0.05). Conclusions The SF level increases in cerebral infarction patients; the level of SF is positively correlated with the severity of carotid atherosclerosis.