A new elemane-type sesquiterpene has been isolated from the roots of Periploca laevigata and its structure elucidated by chemical and spectroscopic methods, principally ¹H and ¹³C nmr. Roots of Periploca laevigata Ait. (Asclepiadaceae), a species widespread in the Mediterranean Sahara, have been indicated as a traditional plant medicine useful in the treatment of diabetes in Tunisia (1-3). A range of cardiotonic glycosides have been isolated from Periploca sepium (4), Periploca graeca (5), and Periploca nigrescens (6). Previous work on P. laevigata has shown the stems to yield tetracyclic and pentacyclic triterpenes and a sterol (7) and, in 1982, some of us published a preliminary account of the structure of a new sesquiterpene (8). The present work describes the confirmation of the latter and, for the first time, its stereochemistry.