Background: Aurantii Fructus Immaturus (AFI) and Aurantii Fructus (AF) are two traditional citrus herbs with health-promoting and nutritive properties. Objective: This paper presents the first attempt to simultaneously investigate the absorption of five major flavanone glycosides, namely narirutin, naringin, hesperidin, neohesperidin, and poncirin, in rat plasma following a single oral administration of AFI and AF extracts to rats. Methods: The plasma concentrations were determined by liquid–liquid extraction followed by a rapid and sensitive ultraperformance LC-tandem mass spectrometry method. Pharmacokinetic parameters were analyzed by noncompartmental modeling using DAS software. Results: The developed method was validated and successfully applied to the pharmacokinetic study of these five flavanone glycosides. Conclusions: The comparison of the pharmacokinetic parameters of flavanone glycosides showed that the absorption of AF extract was lower, while the elimination was relatively rapid, compared with those of AFI extract. Highlights: This study may be useful for further utilization of these two citrus herbs. [ABSTRACT FROM AUTHOR]