Hypotensive events are strongly correlated to the occurrence of perioperative acute kidney injury, but the underlying mechanisms for this are not completely elucidated. We hypothesised that anaesthesia-induced hypotension causes renal vasoconstriction and decreased oxygen delivery via angiotensin II-mediated renal vasoconstriction. Pigs were anaesthetised, surgically prepared and randomised to vehicle/losartan treatment (0.15 mg*kg −1). A deliberate reduction in arterial blood pressure was caused by infusion of propofol (30 mg*kg −1) for 10 min. Renal function and haemodynamics were recorded 60 min before and after hypotension. Propofol induced hypotension in all animals ( p < 0.001). Renal blood flow (RBF) and renal oxygen delivery (RDO 2) decreased significantly regardless of treatment but more so in vehicle-treated compared to losartan-treated ( p = 0.001, p = 0.02, respectively). During recovery RBF and RDO 2 improved to a greater extent in the losartan-treated compared to vehicle-treated (+ 28 ml*min −1, 95%CI 8–50 ml*min −1, p = 0.01 and + 3.1 ml*min −1, 95%CI 0.3–5.8 ml*min −1, p = 0.03, respectively). Sixty minutes after hypotension RBF and RDO 2 remained depressed in vehicle-treated, as renal vascular resistance was still increased ( p < 0.001). In losartan-treated animals RBF and RDO 2 had normalised. Pre-treatment with losartan improved recovery of renal blood flow and renal oxygen delivery after propofol-induced hypotension, suggesting pronounced angiotensin II-mediated renal vasoconstriction during blood pressure reductions caused by anaesthesia.