A stereospecific method of analysis of racemic homoeriodictyol (eriodictyol 3′-methyl ether) in biological fluids is necessary to study pharmacokinetics and disposition in fruits and herbs. A simple high-performance liquid chromatographic method was developed for the determination of homoeriodictyol enantiomers. Separation was achieved in a Chiralcel® OJ-RH column with UV-detection at 288 nm. The standard curves in serum were linear ranging from 0.5 to 100.0 μg/ml for each enantiomer. The mean extraction efficiency was >88.0%. Precision of the assay was <15% (CV), and was within 12% at the limit of quantitation (0.5 μg/ml). Bias of the assay was <15%, and was within 6% at the limit of quantitation. The assay was applied successfully to stereospecific disposition of homoeriodictyol enantiomers in rats and to the quantification of homoeriodictyol enantiomers in Yerba Santa (Eriodictyon glutinosum). © 2007 Elsevier B.V. All rights reserved.