Pakistan top the world Test rankings for the first time after previous incumbents India saw their final Test against the West Indies washed out.
A cursory inspection 30 minutes before the scheduled start time of the final day in Port of Spain revealed that the outfield was still drenched, despite a fourth straight day of warm, dry conditions.
Umpires Nigel Llong and Rod Tucker and match referee Ranjan Madugalle immediately called a halt, leaving both teams in attendance frustrated but Pakistan celebrating.
Mickey Arthur's side had moved to second after drawing their series in England 2-2, and rivals India's stay at the top after going 2-0 up in the Windies series proving short-lived.
Pakistan captain Misbah-ul-Haq told ESPN Cricinfo: "There is no greater feeling than to achieve the number one ranking in the most traditional and purest format of the sport. This is what cricketers play for and want to achieve in their careers.
"I want to compliment everyone who has been involved in the process, including all the players, the support personnel, the management, as well as our loyal fans and followers who remained committed to us and continued to back and support the side through the good and not-so-good days."
Just 22 overs were possible in the Trinidad Test, with the hosts reaching 62 for two on the first morning before the conditions prevented any more play. The four-match series finished 2-0 to India.