In this report, we examined the hepatic microsomal enzyme activity in 34 Saudi patients with chronic liver disease (CLD) and in 21 healthy Saudi subjects by measuring antipyrine clearance (APCI) and the fraction (%) of antipyrine (AP) dose excreted in urine unchanged (fAP) and in the form of its main metabolites: 3-hydroxymethylantipyrine (fHMAP), norantipyrine(fNORAP), and 4-hydroxyantipyrine (f4OHAP). While APCI, fHMAP, fNORAP, f4OHAP were significantly reduced in patients with CLD, fAP was significantly higher in these patients. Correlation was observed between serum albumin and APCI, fHMAP, fNORAP, or f4OHAP and between each two of the last three variables. We conclude that Saudis with CLD have uniform rather than selective reduction of hepatic microsomal enzyme activity and that serum albumin is a sensitive indicator of this activity.