At the time of Diocletian's persecutions, he was a very old man, having served as a reader for sixteen years, then a deacon for twenty-eight years, and finally as a priest for thirty years, for a total of seventy-four years. The pagan judge put him in the Temple of Aesculapius, where large snakes were kept and worshiped as gods. Though the judge meant for Artemon to be attacked by the snakes, the holy priest immobilized them with the sign of the Cross, brought them out of the temple and, in front of the pagan priests, breathed on the snakes, which died instantly. The chief priest, Vitalis, fell to his knees and cried 'Great is the Christian God!' Artemon baptised him along with several of his friends.

The unrepentant judge then condemned Artemon to be thrown into burning pitch, but the judge himself was thrown off his horse into the pitch and died. After this, Artemon went free for a time and spent his time teaching the Faith to his people ("accompanied always by two tame deer," says St Nikolia Velimirovic!). But he was arrested again and beheaded in the year 303.