This study examined the interaction between α1B adrenoceptors and AT1 receptors in the control of renal hemodynamics in rats with pressure overload ventricular hypertrophy. Groups (n=6 each) of male SD rats were subjected to sham surgery (controls) or supra renal aortic banding (AB). On day 45, rats were anaesthetized and prepared for measurement of mean arterial pressure (MAP) and renal cortical blood perfusion (CBP). The changes in CBP caused by intra renal administration of noradrenaline, phenylephrine, methoxamine and ANGII were determined before and after blocking renal α1B adrenoceptors using chlorethylclonidine (CEC). Data, means ± SEM were subjected to ANOVA with significance at P<0.05. Baseline MAP was higher in the AB group, 142±3 vs 105±2 mmHg, but CBP was lower, 624±28 vs 838±21 BPU (both P<0.05), than the control group. The low dose of CEC enhanced the vasoconstrictor responses to methoxamine in the AB group by 10% (P<0.05) compared to the vehicle phase. The high dose of CEC decreased the vasoconstrictor responses to all adrenergic agonists by 10‐20% in the control group versus 30‐60% in the AB group (all P<0.05) and to ANGII by 10% in the control and by 5% in AB group (both P<0.05). These data showed an increased functional importance of renal α1B adrenoceptors in pressure overload hypertrophy through a possible cross talk mechanism with renal AT1 receptors.