The Pakistan Cricket Board have put in place stringent security arrangements for the West Indies team, with 8,000 policemen and paramilitary personnel guarding the visitors in and around the hotel and stadium.
The International Cricket Council (ICC) match referee David Boon will supervise the series while ICC general manager cricket Geoff Allardice and umpires' manager Adrian Griffith will also attend the matches to oversee arrangements.
The series comes as Pakistan is enjoying guarded optimism over the return of international cricket, driven from the country after a deadly militant attack targeting the Sri Lanka team in 2009.
Earlier this month Karachi successfully hosted the final of the popular Pakistan Super League (PSL), becoming the second major venue to host international matches after Lahore hosted Zimbabwe in 2015.
Lahore also hosted the PSL final in March last year, three World XI matches in September and one against Sri Lanka a month later.
This year's PSL final was the first major cricket event in Karachi since 2009. Pakistan captain Sarfraz Ahmed said he was overjoyed at the return of international matches to his home city.
"This is a great occasion," said Sarfraz, the only player in the squad who has played a limited over international in Karachi before.
"We saw a big crowd in the PSl final so I hope they will come in big numbers for the Twenty20 series."
The other two matches will be played on Monday and Tuesday.
Pakistan have done well in the shortest format of the game, having won 14 of the 17 Twenty20 internationals since Sarfraz took over as captain in September 2016.
That helped them reach the number one spot in Twenty20 rankings, having won 2-1 in New Zealand in January this year.
Sarfraz said he hoped his team would keep the momentum.
"Whatever team West Indies sends we have to play at our best because they have good shorter format players," said the captain, whose team has only lost three of their 11 Twenty20 internationals against the West Indies.
Pakistan have included three newcomers in batsman Asif Ali, allrounder Hussain Talat and paceman Shaheen Shah Afridi -- after the trio fared well in the PSL 2018.
West Indies will be without their regular Twenty20 captain Carlos Brathwaite, who opted out of the tour over security fears while openers Chris Gayle and Evin Lewis, allrounders Dwayne Bravo and Kieron Pollard, and spinner Sunil Narine were not available for selection due to their commitments to the Indian Premier League.
Middle order batsman Jason Mohammad will lead the side, which has four uncapped Twenty20 players in batsman Andre McCarthy, fast bowler Odean Smith, left-arm spinner Veerasammy Permaul and all-rounder Keemo Paul.
Pakistan: Sarfraz Ahmed (captain), Ahmed Shehzad, Fakhar Zaman, Babar Azam, Shoaib Malik, Asif Ali, Hussain Talat, Faheem Ashraf, Mohammad Nawaz, Shadab Khan, Mohammad Amir, Hasan Ali, Rahat Ali, Usman Khan Shinwari, Shaheen Shah Afridi.
West Indies: Jason Mohammed (captain), Samuel Badree, Rayad Emrit, Andre Fletcher, Andre McCarthy, Keemo Paul, Veerasammy Permaul, Rovman Powell, Denesh Ramdin, Marlon Samuels, Odean Smith, Chadwick Walton, Kesrick Williams.
ICC match referee: David Boon (Aus)
First Published: March 30, 2018, 1:42 PM IST