Abstract: Four hitherto unknown 6a,11b-dihydroxypterocarpans, namely pterocarpadiols A–D (1–4), were isolated from the ethanol extract of the twigs and leaves of Derris robusta. Their structures were elucidated on the basis of extensive spectroscopic analysis. Pterocarpadiols A–D are a kind of very rare 6a,11b-dihydroxypterocarpans, and their presence as markers may be helpful in chemotaxonomical classification. Graphical Abstract: [Figure not available: see fulltext.]. © 2015, The Author(s).