Six patients, aged 52 to 71 years, with T-tube drainage of the common bile duct and a urinary catheter after cholecystectomy, were studied in order to evaluate the urinary and biliary excretion and pharmacokinetics of cefotiam in the early postoperative period. Each patient received cefotiam 1 g i.v. as a bolus injection. Cefotiam in plasma, urine, and bile were determined by HPLC. A 2-compartment open model with elimination from the central compartment satisfactorily fitted the plasma levels of the drug. The renal clearance of cefotiam (CLR = 133 ml/min) was an order of magnitude greater than its biliary clearance (CLB = 11.8 ml/min). Glomerular filtration was the main mechanism for elimination of cefotiam. The values of CLR and CLB in relation to the total plasma clearance (CL = 138. ml/min) demonstrated the negligible role of metabolism in elimination of cefotiam in these patients.