OBJECTIVE Volume expansion and inotropic support with catecholamines are sometimes insufficient to ensure adequate blood pressure and cerebral perfusion in acute liver failure (ALF). The aim of this study was to determine if terlipressin increases cerebral perfusion, cerebral concentration of lactate and intracranial pressure (ICP), and to compare the effect with that of noradrenalin (NA). METHODS Ten patients (median age 42.5 yr; range 15-66; 5 women) who needed inotropic support and had an ICP and a cerebral microdialysis catheter placed had concomitant recording of cerebral perfusion pressure (CPP), cerebral perfusion (using transcranial Doppler sonography (V(mean))) and ICP. Also cerebral extracellular concentration of lactate ([lactate]ec) and pyruvate ([pyruvate]ec) was collected before and after an increase in the NA infusion rate and/or i.v.-injection of 1mg terlipressin. RESULTS Both NA and terlipressin increased CPP and V(mean) (p<0.01). Also ICP increased during NA infusion (p<0.01) but not after terlipressin. The cerebral [lactate]ec decreased after terlipressin injection from 2.34 (1.52-8.38) to 1.99 (0.03-4.83)mmol/l (p=0.027) but not during NA infusion (2.83 (1.53-7.11)mmol/l). The [lactate]ec to [pyruvate]ec ratio remained unchanged in both the NA group (20.7 (13.2-40.0)) and terlipressin group (22.2 (10.5-30.0)). CONCLUSIONS This study shows that terlipressin increases CPP and cerebral perfusion with little influence upon ICP and cerebral [lactate]ec in ALF patients. These findings indicate that terlipressin may be valuable, as an additive treatment to NA infusion to secure brain viability.