It is known from ancient sources that “laurel,” identified with sweet bay, was used at the ancient Greek oracle of Delphi. The Pythia, the priestess who spoke the prophecies, purportedly used laurel as a means to inspire her divine frenzy. However, the clinical symptoms of the Pythia, as described in ancient sources, cannot be attributed to the use of sweet bay, which is harmless. A review of contemporary toxicological literature indicates that it is oleander that causes symptoms similar to those of the Pythia, while a closer examination of ancient literary texts indicates that oleander was often included under the generic term laurel. It is therefore likely that it was oleander, not sweet bay, that the Pythia used before the oracular procedure. This explanation could also shed light on other ancient accounts regarding the alleged spirit and chasm of Delphi, accounts that have been the subject of intense debate and interdisciplinary research for the last hundred years.