Delirium is a common complication of vascular surgery. The protective effect of preoperative statins on delirium after vascular surgery is controversial. The authors hypothesized that preoperative statin administration would decrease the incidence of delirium after vascular surgery. From May 2010 to May 2015, 1,132 patients underwent vascular surgery. Postoperative delirium was diagnosed from patients' medical records. The incidence of delirium was 11.5%. The preoperative statin exposure was not associated with reduced delirium in the univariate analysis. After adjusting for covariates, preoperative statin exposure was associated with reduced delirium (OR, 0.54; 95% CI, 0.33-0.87; p = 0.011). This favor effect of statin for delirium was observed after propensity matching (OR, 0.59; 95% CI, 0.34-1.02; p = 0.060). However, the median hospital lengths of stay and in-hospital mortality were not statistically different between the two groups. CRP(C-reactive protein) levels in the unmatched population were lower in the preoperative statin group compared with the other group (p<0.001), however, there was only numerically different without statistical difference after matching (p = 0.083). Preoperative statin use was associated with a decreased incidence of postoperative delirium in patients who underwent vascular surgery. However, preoperative statin did not reduce mortality rate and hospital stay.