Rain covers are removed ahead of pitch inspection at Bristol County Ground on Friday. Reuters
The game was scheduled to begin at 10:30 (0930 GMT) but was eventually called off in the afternoon, with both teams being awarded a point.
It is the first match at the World Cup in England and Wales to be abandoned without a result.
Pakistan cricket fans hold the national flag as rain delays start of play at Bristol County Ground on Friday. AFP
Both teams now have three points, with one win and a loss apiece.
Pakistan lost to the West Indies by seven wickets at Trent Bridge before beating England by 14 runs at the same venue on Monday.
Sri Lanka crashed to a 10-wicket defeat against New Zealand before pulling off a 34-run win against Afghanistan in a rain-affected game.
The call-off upset fans who had travelled to watch the game.
"We came from Lahore to watch this match and it proved a damp squib," said Farhan Malik. "We lost a crucial point because we were sure of beating Sri Lanka."
Pakistan coach Mickey Arthur praised his team's resolve after a "shocking" defeat in their tournament opener.
Sri Lanka started the tournament as rank outsiders and finished sixth of the nine teams, registering one of their three wins against the world's top-ranked one-day international side and hosts England.
Sarfaraz Ahmed's side needed to smash the world record for margin of victory in a one-day international but, after winning the toss at Lord's, they failed to muster enough runs to give them a chance.
Bangladesh must be all out for seven or lower if Pakistan are to deny New Zealand a place in the semi-finals alongside Australia, India and England.
"The decision has been taken to ensure protection of all the Race's participants," said the Higher Organising Committee, adding that "safety comes at the top of all priorities."
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Defending champions Quetta Gladiators produced a stunning run-chase to defeat Islamabad United by five wickets in the first-ever HBL Pakistan Super League