The Brazilian-born player made a name for himself initially with FC Porto, where he won the Champions League in 2004 under the guidance of Jose Mourinho.
His performances for the Portuguese club earned him a move to Barcelona later that summer and he would go on to spend four years at the Camp Nou, winning two La Liga titles and another European Cup in the process.
However, at the age of 35, he has decided that he can no longer continue to train and play matches on a regular basis.
"My wish was to continue the campaign with Fluminense, but my body cannot handle pressure any more. I therefore announce my retirement," he said in a statement.
Deco made 75 appearances for Portugal at international level, scoring five goals.