Arterial stiffness occurs early in the atherosclerotic process; however, few data are available concerning risk factors for arterial stiffness in youth with diabetes. We identified factors associated with arterial stiffness in youth with diabetes and assessed the effects of these factors on the relationship between arterial stiffness and diabetes type (type 1 vs. type 2). A subset of patients from the SEARCH for Diabetes in Youth study with type 1 (n = 535) and type 2 diabetes (n = 60), aged 10-23 years (52% male; 82% non-Hispanic white; diabetes duration 65 +/- 49 months) had arterial stiffness, anthropometrics, blood pressure, fasting lipids, and A1C measured. Arterial stiffness was measured by brachial distensibility (brachD), pulse wave velocity (PWV), and augmentation index adjusted to heart rate of 75 beats/min (AI75). Youth with type 2 diabetes had worse brachD (5.2 +/- 0.9 vs. 6.1 +/- 1.2%/mmHg), PWV (6.4 +/- 1.3 vs. 5.3 +/- 0.8 m/s), and AI75 (6.4 +/- 9.9 vs. 2.2 +/- 10.2%) than those with type 1 diabetes (P < 0.01 for each). These differences were largely mediated through increased central adiposity and higher blood pressure in youth with type 2 diabetes. We also found a pattern of association of arterial stiffness measures with waist circumference and blood pressure, independent of diabetes type. Youth with type 2 diabetes have worse arterial stiffness than similar youth with type 1 diabetes. Increased central adiposity and blood pressure are associated with measures of arterial stiffness, independent of diabetes type. Whether these findings indicate that youth with type 2 diabetes will be at higher risk for future complications requires longitudinal studies.