A maladaptive carotid remodeling was described in type 2 diabetes mellitus. However, it is still unknown whether it is a feature of diabetes per se, or rather a consequence of the frequent comorbidity with hypertension. We therefore studied the impact of diabetes, hypertension, and their combination on carotid geometry and remodeling, recruiting to this aim 139 subjects (31 normotensives-NT, 38 hypertensives-HT, 24 diabetic normotensives-DMNT, and 46 diabetic hypertensives-DMHT). Common carotid diameter, intima-media thickness (IMT) and distension were determined using a real-time echo-tracking system “Carotid Studio”. Local pulse pressure was obtained by applanation tonometry. Carotid static and pulsatile circumferential wall stress was calculated by Lamé equations. IMT was increasingly higher in the four groups, reaching the highest value in DMHT. As compared to NT, carotid lumen diameter was increased in HT and DMHT, but not in DMNT. HT showed significantly higher circumferential static wall stress than DMHT, while DMNT and NT had similar and significantly lower values. Carotid pulse pressure was similarly increased in DMHT and HT. In a logistic regression model adjusted for confounders, hypertension carried an increased risk (OR 2.33; CI-95% 1.02–5.63) of a widened lumen diameter, whereas diabetes carried an increased risk of IMT above the median value (OR2.49; 1.09–5.68). Hypertension, but not diabetes, was associated to an increased static and pulsatile stress (OR7.74; 2.76–21.72, and 4.86; 1.95–12.10). In conclusion, maladaptive remodeling, previously reported in diabetic patients, is conceivably attributable to the concomitant presence of hypertension.