The 26-year old has joined from homeland club Deportes Tolima after some initial problems that prevented him from departing Ibague-based outfit.
Tolima still owned Perlaza's rights when he first wanted to join the Timbers but the US club has since been able to sort out terms with the Colombians and he has now joined the team he has ben training with since January.
Perlaza, who scored 15 goals in 23 starts last season, will bring plenty to the Timbers forward setup according to technical director Gavin Wilkinson.
"With his athleticism and how tough he plays, we think he is a great fit for the Timbers," said Wilkinson.
"He was a tremendous goal scorer last year for Tolima, and he already has shown he has the ability to be the same with Portland this season."