Fasting serum levels of total 3αhydroxy bile acids were measured in 163 consecutive patients, who clinically were suspected of having a hepatobiliary disorder. By means of routine biochemical liver tests and paraclinical investigations the clinical suspicion was confirmed in 95 patients and disproved in the other 68 patients. A comparison between this diagnostic grouping and the serum bile acids levels showed that the predictive value of serum concentrations above a discrimination value of 10 μmol/l - that is, the predictive value of a positive test - was 1.0 (0.94-1.0), whereas the corresponding predictive value of a negative test was 0.66 (0.56-0.75). Thus, fasting serum levels of total 3αhydroxy bile acids may be used as a highly specific and moderately sensitive diagnostic test for hepatobiliary disorders. Furthermore, the study showed that the nosographic sensitivity of total 3αhydroxy bile acids in patients with verified cirrhosis was significantly greater than that of serum bilirubins and not significantly different from those of the other routine biochemical liver tests.