The Pakistan team poses with the winners' trophy after the 3rd T20I.
It will be the first global matches in Karachi since Sri Lanka played a Test match in 2009 when the visiting team came under terrorist attack in Lahore and Pakistan became virtually a no go-zone area for foreign teams.
"Karachi last hosted an global cricket match in 2009 when Pakistan and Sri Lanka played the first of their three-match Test series at the National Stadium. These bilateral (series) will be a part of the FTP, since we've made this agreement", PCB Chairman Najam Sethi said.
West Indies are the reigning World Twenty20 champions after winning the title in India in 2016.
The PCB had been trying to convince foreign teams to restart global cricket back in Pakistan. "Good news is that West Indies will play three games, on [April, 1, 2 and 4], but these matches will be played in Karachi".
Karachi will also host the PSL final on 25 March, while Lahore will host two play-off games on 20 and 21 March. That is how we intend to put Karachi back on the cricket map once again.
The National Stadium has undergone renovation and will be ready for the final soon, said Sethi.
Sethi said Reg Dickason, the ICC's security consultant, would visit Karachi during the PSL final to look at the security arrangements for the series.