Acute fatty liver of pregnancy is a rare disease which may be letal if diagnosis is missed. The pathogenesis is not completely clear, but there is some evidence that some cases have been associated with a genetic deficiency of fatty acid beta-oxidation. Other predisposing factors include primiparity, multiple pregnancy, male fetal sex and pre-eclampsia. Clinical presentation and laboratory findings are often unspecific. Increasing serum aminotransferases are characteristic in the early stage of the disease. Liver biopsy establishes the diagnosis and typically shows microvesicular, centrilobular fatty changes of hepatocytes. Differential diagnosis includes the HELLP-Syndrome, cholestasis of pregnancy, pre-eclampsia and viral or drug induced hepatitis. Without adequate treatment liver failure with coagulopathy and encephalopathy may develop. Two cases of acute fatty liver in pregnancy in an early stage are presented. Clinical and histopathological findings as well as diagnostic and therapeutic procedures are discussed.