Theriac is a term referring to medical compounds that were originally used by the Greeks from the first century A.D. to the nineteenth century. The term derived from ancient Greek thēr (θήρ), 'wild animal'. Nicander of Colophon (2nd century BC) was the earliest known mention of Theriac in his work Alexipharmaka (Αλεξιφάρμακα), 'drugs for protection'. During the era of King Mithridates VI of Pontus (132-63 BC), the universal antidote was known as mithridatium (μιθριδάτιο or mithridatum or mithridaticum) in acknowledgment of the compound's supposed inventor or at least best-known beneficiary. It contained around forty ingredients, such as opium, saffron, castor, myrrh, cinnamon and ginger. Theriac was not only used as an antidote from poisoning but also for various diseases, such as chronic cough, stomachache, asthma, chest pain, fever, colic, seizures, diarrhea, and retention of urine. The present study aims to collect and discuss the mentions of theriac in Persian medical texts.