The influence of biochemical parameters of hepatic function on vancomycin pharmacokinetics was retrospectively evaluated in 76 adult patients (age 18 to 81 years), from biochemistry data gathered during routine therapeutic drug monitoring. All subjects had normal serum creatinine levels. Vancomycin concentrations were determined by fluorescence polarization immunoassay in 101 paired serum samples. All data for vancomycin concentration versus time were fitted to a one-compartment model using the bayesian approach. Bilirubin, transaminases (n = 101), gamma-glutamyl transferase (n = 97), alkaline phosphatase (n = 95), albumin (n = 92) and lactate dehydrogenase (n = 42) were determined. No strong correlation was seen between any of the pharmacokinetic and biochemistry parameters studied. In patients with hyperbilirubinaemia, the mean Vss and t1/2 were increased (Vss: 0.75 +/- 0.31 versus 0.92 +/- 0.42 1.kg-1, p = 0.020; t1/2 5.93 +/- 3.30 versus 7.48 +/- 4.44 hr, p = 0.049). When liver function was evaluated according to hepatic profile (normal, mildly altered and severely altered), no significant differences were observed in vancomycin pharmacokinetics among the groups. In conclusion, vancomycin pharmacokinetics are only weakly influenced by the biochemistry parameters of liver function.