Democedes, a Greek physician, born at Cro-tona, in Magna Graecia, about 550 B. C. The severity of his father, Calliphon, caused him to leave his home and settle at AEgina, where he was very successful. Thence he went on invitation to Athens, and soon afterward he entered the service of Polycrates, tyrant of Samos. Accompanying his patron on his visit to Orcetes, satrap of Sardis, he was seized with him by the latter, who put Polycrates to death, and sent Democedes as a slave to Susa, where he suddenly gained great favor and rich rewards by successfully curing the sprained foot of Darius Hystaspis, after that monarch's own physicians had failed. Democedes wished to return home, but the king would not grant him permission. Atossa, the principal wife of Darius, was afflicted with a tumor on the breast, and called in the Greek, who promised to cure her if she would swear to do for him anything he might ask. The cure having been effected, he asked permission to return to Greece; and the queen induced Darius to send him thither, accompanied by 15 Persians, on a secret mission to ascertain the best points of attack for an expedition planned by the Persians. The Greek promised to return, and in order to delude the king refused to take any of his own property, saying he should like to find things as they were on coming back to Susa, Laden with rich presents, he went to Sidon, where he and his comrades embarked, and a survey of Greece was made (518). Passing to Italy, Democedes persuaded Aristophilides, ruler of Tarentum, to seize the Persians as spies, while he continued his journey to Crotona. The Persians were soon released, proceeded to Crotona, and seized Democedes in the market place; but he was rescued by his fellow citizens, who also robbed the Persians of their store ship.

He remained in his home, and married the daughter of the wrestler Milo. Democedes is said to have written a work on medicine, and his professional reputation was almost equal to that of Hippocrates.