Our objective was to determine the relationships between levels of different dietary nutrients intake with circulating endothelial progenitor cells (EPC) and vascular endothelial function in type II diabetic patients. We studied the daily dietary nutrients intake, the numbers of circulating CD34(+)/KDR(+) EPC and CD133(+)/KDR(+) EPC and brachial artery flow-mediated dilation (FMD) in 88 diabetic patients without prior cardiovascular diseases and 91 sex- and age-matched controls. Compared with controls, diabetic patients had lower CD133(+)/KDR(+) EPC count (48.3 +/- 5.2 vs. 84.6 +/- 7.6/microL, p < 0.001), CD34(+)/KDR(+) EPC count (311 +/- 41 vs. 412 +/- 36/microL, p = 0.045), and FMD (2.54 +/- 0.37% vs. 5.46 +/- 0.47%, p < 0.001). After adjusted for age, sex, smoking history, body weight, hemoglobin A1c level, total calorie intake, other dietary vitamin intake, use of antihypertensives, and lipid lowering agents, a higher intake of thiamine was significantly associated with a higher level of circulating CD34(+)/KDR(+) EPC (beta = 0.49, p = 0.028) and CD133(+)/KDR(+) EPC (beta = 0.45, p = 0.037) in diabetic patients, but not in controls. Furthermore, an increased intake of thiamine from 1st to 4th quartile in diabetic patients independently predicted an absolute increase in FMD by 1.29% (p = 0.026, relative increase = 63.5%). This study demonstrated that daily thiamine intake was positively correlated with the circulating number of EPCs and FMD in patients with type II diabetes, independent of other dietary nutrients intake.