Tiago quits international football
The 29-year-old, currently on loan from Juventus to Atletico Madrid, made his international debut in a friendly against Scotland in 2002 and went on to earn 58 caps and score three goals for Portugal.
In a letter published on the FPF website, Tiago said the move was also designed to "make room for opportunities for younger players" in the Portugal team.
He is the fifth player to quit the national team after last year's World Cup, following in the steps of midfielder Deco, winger Simao, and defenders Miguel and Paulo Ferreira.
Tiago was an unused substitute in the Euro 2004 squad and played in the 2006 and 2010 World Cups. He scored two goals in Portugal's 7-0 rout of North Korea in South Africa.