Amauri Carvalho de Oliveira, 29, applied for the citizenship after his Brazilian-born wife, Cynthia Cosini Valaderes, obtained it in March through his Italian ancestors.
The striker said he would be pleased to play with the Azzurri, although in January he appeared set on playing his first game with Brazil, which would make him unavailable for the Azzurri.
Juventus, which he joined in 2008, denied him the permit to accept the call of Brazil coach Dunga, claiming it was sent too late.
With three qualifiers left, the world champions Azzurri lead Group 8 one point ahead of Ireland, who host them in October in one of their two remaining games.