The disposition of ceftazidime was assessed in 11 surgical patients with suspected intra-abdominal infection. All patients had normal hepatic function, and creatinine clearances ranged from 43 to 186 ml/min. Patients received 2 g of ceftazidime intravenously every 8 h. Trough and peak concentrations in serum were measured on day 2, and trough and postdose concentrations in serum were determined on 10 samples collected during a dosage interval between days 3 and 6 of therapy. Ceftazidime peak and trough concentrations in serum at steady state determined by high-performance liquid chromatography were 257.4 ± 122.0 (mean ± standard deviation) and 13.1 ± 20.6 mg/liter. The serum-concentration-versus-time profile was multiexponential. The elimination half-life, steady-state volume of distribution, and total body clearance were 2.52 ± 1.39 h, 0.31 ± 0.12 liter/kg, and 0.11 ± 0.05 liter/h per kg, respectively. Total predicted body clearance significantly correlated with the measured values (r = 0.686; P = 0.001). The disposition of ceftazidime is dependent on creatinine clearance and is not significantly altered by surgery or acute infectious processes.