This study aims to decipher the potential effects of nebivolol in prevention and/or regression of renal artery dysfunction in diabetes associated with hypertension. Renal arteries were isolated from 80 male mice divided into four experimental groups: (i) group D: diabetics, at 2months since streptozotocin injection; (ii) group Din: mice that at the initiation of streptozotocin diabetes were treated with 10mg/kg b.w./day nebivolol for 2months, to test for the potential prevention of vascular dysfunction; (iii) group Dfin: mice that after 2months of diabetes were treated daily with 10mg/kg b.w./day nebivolol for additional 2months, in order to follow the possible regression of the dysfunction, and (iv) controls (C), age-matched healthy animals. The following measurements were performed: arterial blood pressure, plasma glucose concentration, and the vascular reactivity of the renal arteries in response to noradrenaline (10^{− 4}M), acetylcholine (10^{− 4}M) and sodium nitroprusside (10^{− 4}M). To assess the molecular mechanisms involved in the reactivity of the renal artery, the contribution of mitogen-activated protein kinase (MAP kinase) pathway and of L-type voltage gated Ca²⁺ channels (in the contractile response to noradrenaline), of nitric oxide (NO) and Ca²⁺ activated K⁺ channels (in the endothelium-dependent vasodilator response), and of cGMP (in the endothelium-independent vasodilator response) was examined by exposing the arteries to corresponding inhibitors, and by using myograph and patch-clamp techniques, immunoblotting and NO assays. Results showed that, group D was characterized by hyperglycemia (blood glucose concentration: 136.66 ± 4.96mg/dl, a value ∼ 65% increased compared to group C) and hypertension (systolic blood pressure: 145.66 ± 5.96mm Hg, a value ∼ 34% increased compared to group C). Compared to group D, group Din was characterized by diminished blood glucose concentration (∼ 1.6 fold), reduced systolic and diastolic blood pressure (∼ 1.3 fold) and heart rate (∼ 1.6 fold), as well as by increased contractile response of the renal artery to noradrenaline (∼ 1.84 fold) and of the impeded vasodilator response to acetylcholine (∼ 1.81 fold) and sodium nitroprusside (∼ 1.42 fold). Together, these effects demonstrate that administration of 10mg/kg b.w./day nebivolol at the moment of diabetes induction has preventive effects, ameliorating diabetes dysfunctions. Compared to group D, group Dfin was characterized by diminished glucose concentration (∼ 1.3 fold), reduced systolic and diastolic blood pressure and heart rate (both ∼ 1.2 fold), and by augmentation of contractile response of the renal artery to noradrenaline (∼ 1.62 fold) and of vasodilator response to acetylcholine (∼ 1.13 fold) and sodium nitroprusside (∼ 1.19 fold). These effects assess that administration of 10mg/kg b.w./day nebivolol after 2months of diabetes contributes to regression of diabetes-associated dysfunctionalies. Nebivolol influenced the molecular mechanisms involved in renal artery reactivity in diabetic and hypertensive mice: it increased the NO production and endothelial NO synthase (eNOS) protein expression, decreased the expression of ∝ protein in L-type calcium channels and Ca²⁺ activated K⁺ channels, and diminished the MAP kinase activity. The reported data suggest that nebivolol may offer additional vascular protection for treating diabetes associated with hypertension.