Islamic pharmacology included numerous plant-derived substances, especially from South and Southeast Asia, that were unfamiliar in ancient Greek and Roman times. The arrival of these newmateria medica is commonly accepted to be a consequence of the expanding horizons of trade in the Islamic period. Closer examination, however, reveals that many of these substances are in fact attested in pre-Islamic times. In addition, the philological evidence of the names of thesemateria medica in Arabic frequently shows that their path into the Near East occurred through Persian culture. These factors suggest that we must look to the pre-Islamic Sasanian period for the context of the arrival of many of the new so-called Islamic drugs.