"Geoff Lawson has been sacked. He has been given three months' severance pay," PCB spokesman Raza Rashid told AFP.
The move comes just three days after new PCB chairman Ijaz Butt said that Lawson's contract would not be renewed next year, on the grounds that Pakistan had "no utility" for him.
The 50-year-old Lawson was appointed Pakistan coach in July last year after Pakistan's first-round defeat in the World Cup in the Caribbean in March.
Calls for his removal intensified when Pakistan lost to Sri Lanka in the final of the T20 four-nation event in Canada earlier this month.
Butt had said that Lawson could not be instantly removed for financial reasons.
Pakistan must now look for a new coach before a Test series against India at home in January-February next year.