<jats:title>Abstract</jats:title><jats:p><jats:italic>Teucrium</jats:italic> species, such as germander, are rich in <jats:italic>neo</jats:italic>‐clerodane diterpenoids and have been used in traditional folk medicine for their stimulant, diuretic, antipyretic and antiseptic properties. However, the furano <jats:italic>neo</jats:italic>‐clerodane diterpenoids present in germander have been implicated in the <jats:italic>in vivo</jats:italic> hepatotoxicity of this botanical. In this study, authenticated germander (<jats:italic>Teucrium chamaedrys</jats:italic> L. and <jats:italic>Teucrium canadense</jats:italic> L.) was used as the source material. Methanol extracts of powdered plant material were prepared and analysed by HPLC using Synergi<jats:sup>®</jats:sup> Max‐RP columns with monitoring at 220 nm. Limited amounts of teucrin A and other diterpenoid standards were analysed on a Synergi Max‐RP column in order to determine their retention times and to generate calibration curves. The same standards were subjected to concurrent mass spectral analysis. Teucrin A and diterpenoids such as dihydroteugin, teuflin, teuflidin and teucvidin were tentatively identified in the plant extracts by HPLC‐MS and <jats:sup>1</jats:sup>H‐NMR experiments. For the isolation of teucrium diterpenoids on a semipreparative scale, a solid‐phase extraction method was developed for the first time using styrene divinylbenzene and strata‐X sorbents for teucrin A and teuflin, respectively. Semi‐preparative HPLC of the methanol extract of the powdered aerial parts of <jats:italic>Teucrium</jats:italic> plants was carried out on a semipreparative Synergi Max‐RP column with photodiode array detection in order to confirm the identities of some diterpenoids by HPLC‐MS and NMR. Copyright © 2006 John Wiley & Sons, Ltd.