Objective To analyze the correlation of serum vitamin D3 level with peripheral arterial sclerosis (PAS) in the very old patients with hypertension. Methods A total of 166 very old patients with primary hypertension (85.5±4.9 years old, 75-99) admitted in our department from September 2011 to November 2012 were enrolled in this study. With serum 25(OH)D3 level lower than 20 ng/ml as diagnostic criteria for vitamin D3 deficiency, these patients were divided into low level group (n=118) and normal group (n=48). Ambulatory 24-hour blood pressure monitoring and lower extremity arteries ultrasonography were performed to evaluate the severity of PAS. The correlation between serum vitamin D3 level and PAS severity was analyzed. SPSS statistics 16.0 was employed for data analysis. The measurement data were expressed as mean±standard deviation ([AKx-D]±s), and Student’s t test was employed for the comparison between groups. Enumeration data were expressed as percentage, and inter-group comparison was carried out with Chi-square test. Related risk factors of lower extremity arterial stenosis were analyzed by logistic regression analysis. Results Compared with the normal group, the low level group had higher level of low-density lipoprotein cholesterol (LDL-C), lower diastolic blood pressure (DBP), higher pulse pressure, and higher incidences of PSA and hyperlipidemia (P<0.05). The results of logistic regression analysis showed that PAS was negatively correlated with serum 25(OH)D3(OR=0.780,5%CI 0.670-0.890; P=0.039) and DBP(OR=1.030,5%CI 0.929-0.983; P=0.040), but positively correlated with LDL-C (OR=2.446,5%CI 1.138-1.312; P=0.043). Conclusion Serum vitamin D3 level is in obvious correlation with PAS in the very old patients with hypertension.