Abstract: AIM To develop a liquid chromatography-electrospray ionization tandem mass spectrometry method for rapid analysis of terbutaline at level of 50 pg·mL^-1 in human plasma. METHODS Samples containing terbutaline and salbutamol (internal standard, IS) were extracted using C₁₈ solid-phase extraction cartridges, followed by liquid chromatographic separation and mass spectrometric detection. The mobile phase consisted of acetonitrile-water-formic acid (20∶80∶1), at a flow-rate of 0.4 mL·min^-1. Selected reaction monitoring with mass transitions m/z 226→151 and m/z 240→148 were used for terbutaline and IS, respectively. RESULTS The chromatographic analysis time for each sample was approximately 3.8 min. The assay was linear from 0.05 to 8.0 ng·mL^-1. The between-run precision and accuracy of the quality controls (QCs, 0.1, 0.4 and 4.0 ng·mL^-1) were characterized by relative standard deviation (RSD) of 2.5% to 7.1% and relative errors of -3.1% to 5.7%, respectively. The within-run precision of QCs was characterized by RSD of 4 2% to 6 6%. This method was applied to the analysis of samples taken up to 60 h after oral administration of 10 mg bambuterol in healthy volunteers. CONCLUSION The method is shown to be suitable for clinical investigation of terbutaline pharmacokinetics, which offers advantages of specificity, speed, and greater sensitivity over previously reported methods.