Patients with cirrhosis have a hyperdynamic circulation with an abnormally distributed blood volume and widespread arteriovenous communications. The aim of the present study was to detect possible very early (i.e. below 4 sec) and early (i.e. above 4 sec) central circulatory transits and their potential influence on determination of the central blood volume. Thirty-six patients with cirrhosis and 19 control subjects without liver disease undergoing haemodynamic catheterisation were given central bolus injections of albumin with different labels. Exponential and gamma variate fits were applied to the indicator dilution curves, and the relations between flow, circulation times, and volumes were established according to kinetic principles. No significant very early central circulatory transits were identified. In contrast, early (i.e. 4 sec to maximal) transits corresponding to a mean of 5.1% (vs. 0.8% in controls, p<0.005) of cardiac output (equivalent to 0.36 vs. 0.05 L/min, p<0.01) were found in patients with cirrhosis. These early transits averaged 7.7 sec vs. 12.7 and 17.2 sec of ordinary central transits of cirrhotic patients and controls, respectively (p<0.001). The early transits were directly correlated to the alveolar-arterial oxygen difference in the cirrhotic patients (r=0.46, p<0.01), but not in the controls (r=0.04, ns). There was a good agreement between the central blood volume determined by the conventional indicator dilution method and that determined by separation of early and ordinary transits by the gamma variate fit method (1.51 vs. 1.53 L, ns). In conclusion no very early central circulatory transits were identified in patients with cirrhosis. A significant part of the cardiac output undergoes an early transit, probably through pulmonary shunts or areas with high ventilation-perfusion ratios in patients with cirrhosis. Composite determination of central blood volume by the gamma variate fit method is in close agreement with established kinetic methods. The study brings further evidence of an abnormal central circulation in cirrhosis.