He wooed Findabair, daughter of Ailill and Medb. When he was severely wounded by a water monster, a hundred and fifty maidens of the sidhe, all dresed in green, carried him off, and bore him back the following morning, fully healed. He refused to pay a bride-price for Findabair but agreed to accept her if he helped Medb beat the Ulstermen in the Táin Bó Cuailnge (Cattle Raid of Cooley).
He fought for Ailill and Medb in the Táin Bó Cuailnge (Cattle Raid of Cooley), during which he was drowned in a river in single combat with Cúchulainn. His body was borne away by a hundred and fifty maidens of the sidhe, all dressed in green.
The mound of Carnfree (Irish Carn Fraoich, Fráech's cairn) near Tulsk in County Roscommon, which was used for the inauguration of the O'Connor kings of Connacht, preserves his name. The Cave of Cruachan nearby contains an ogham inscription in primitive Irish reading VRACCI MAQI MEDVVI, (the cave) of Fráech son of Medb.