Cardiac surgery performed with cardiopulmonary bypass (CPB) may be complicated by hypotension due to low systemic vascular resistance (SVR). Often in those cases, hypotension is resistant to pressor catecholamines. We report six cases of norepinephrine-resistant postcardiotomy hypotension, treated by terlipressin (TP), a potent vasopressor agent. Between May 2007 and May 2008, we treated six patients with TP administration (1 mg bolus) for post CPB refractory vasodilatory hypotension. Analyzed parameters were: mean arterial pressure (m-AP), SVR, cardiac output index (CI), mean pulmonary pressure (m-PP), and lactate, at baseline (before TP bolus) and 3 h after injection. Before TP bolus, the average m-AP was 53.32+/-8.86 mmHg, the CI was 3.45+/-0.24 l/min/m(2), the SVR was 650+/-62.03 dyne*s/cm(5) and the arterial lactate level was 4.6+/-0.95 mmol/l. Three hours after the TP bolus, the m-AP increased to 81.83+/-9.71 mmHg (P=0.002), the CI decreased to 2.88+/-0.14 l/min/m(2) (P=0.002), the SVR increased to 1154+/-116 dyne*s/cm(5) (P=0.002), and arterial lactates decreased to 3.13+/-0.78 mmol/l (P=0.015), without significant modification of m-PP and CVP. We treated postoperative refractory low SVR hypotension by TP administration in bolus. Exogenous administration of TP normalized SVR and increased the systemic arterial pressure with a minimum effect on pulmonary pressure. Subsequently, the effect on systemic blood pressure enhanced urine output. No major collateral effects were observed. The administration of TP in bolus may result as a useful alternative for treating refractory low SVR hypotension post CPB.