Acute liver failure and septic shock share many clinical features, including hyperdynamic cardiovascular collapse. Adrenal insufficiency may result in a similar cardiovascular syndrome. In septic shock, adrenal insufficiency, defined using the short synacthen test (SST), is associated with hemodynamic instability and poor outcome. We examined the SST, a dynamic test of adrenal function, in 45 patients with acute hepatic dysfunction (AHD) and determined the association of these results with hemodynamic profile, severity of illness, and outcomes. Abnormal SSTs were common, occurring in 62% of patients. Those who required noradrenaline (NA) for blood pressure support had a significantly lower increment (median, 161 vs. 540 nmol/L; P <.001) following synacthen compared with patients who did not. Increment and peak were lower in patients who required ventilation for the management of encephalopathy (increment, 254 vs. 616 nmol/L, P <.01; peak, 533 vs. 1,002 nmol/L, P <.01). Increment was significantly lower in those who fulfilled liver transplant criteria compared with those who did not (121 vs. 356 nmol/L; P <.01). Patients who died or underwent liver transplantation had a lower increment (148 vs. 419 nmol/L) and peak (438 vs. 764 nmol/L) than those who survived (P <.01). There was an inverse correlation between increment and severity of illness (Sequential Organ Failure Assessment, r = -0.63; P <.01). In conclusion, adrenal dysfunction assessed by the SST is common in AHD and may contribute to hemodynamic instability and mortality. It is more frequent in those with severe liver disease and correlates with severity of illness.