A rapid, sensitive and simple high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for determination of cefazedone in human plasma using metronidazole as internal standard (IS). The chromatographic separation was achieved on an Ultimate XB-CN column (2.1 mm x 150 mm, 5 mu m) with an isocratic mobile phase of acetonitrile and 20 mM ammonium acetate in 0.1% formic acid in water (15:85, v/v). Detection was performed using electrospray ionization in positive ion multiple reaction-monitoring mode (SRM), monitoring the transitions m/z 548.2 -> 344.1 for cefazedone and m/z 172.2 -> 128.1 for IS. Calibration curves were linear over a wide range of 0.20-401.12 mu g/mL for cefazedone in plasma. The lower limit of quantification (LLOQ) was 0.20 mu g/mL. The intra- and inter-day precisions were less than 7.2%. The average recovery of cefazedone was 90.8-91.0%. The validated method was successfully applied to the pharmacokinetic study of cefazedone in Chinese healthy volunteers following intravenous (IV) administration of 500, 1000 and 2000 mg cefazedone injection. (C) 2010 Elsevier B.V. All rights reserved.