The equilibrium pressure obtained during simultaneous occlusion of hepatic vascular inflow and outflow was taken as the reference estimate of hepatic vascular distending pressure (P_hd). P_hd at baseline was 1.1 ± 0.2 (mean ± SE) mmHg higher than hepatic vein pressure (P_hv) and 0.7 ± 0.3 mmHg lower than portal vein pressure (P_pv). Norepinephrine (NE) infusion increased P_hd by 1.5 ± 0.5 mmHg and P_pv by 3.7 ± 0.6 mmHg but did not significantly increase P_hv. Hepatic lobar vein pressure (P_hlv) measured by a micromanometer tipped 2-Fr catheter closely resembled P_hd both at baseline and during NE-infusion. Dynamic pressure-volume (PV) curves were constructed from continuous measurements of P_hv and hepatic blood volume increases (estimated by sonomicrometry) during brief occlusions of hepatic vascular outflow and compared with static PV curves constructed from P_hd determinations at five different hepatic volumes. Estimates of hepatic vascular compliance and changes in unstressed blood volume from the two methods were in close agreement with hepatic compliance averaging 32 ± 2 ml · mmHg¹ · kg liver¹. NE infusion reduced unstressed blood volume by 110 ± 38 ml/kg liver but did not alter compliance. In conclusion, P_hlv reflects hepatic distending pressure, and the construction of dynamic PV curves is a fast and valid method for assessing hepatic compliance and changes in unstressed blood volume.