The first flight PK 894 operated by Boeing 777 aircraft tookoff from Islamabad carrying more than 300 passengers in the early hours of Monday morning, said a spokesman for the PIA.
The passengers were seen off by PIA officials at Islamabad International Airport.
The flight operation to Kuala Lumpur has been restored after eight months following its suspension due to closure of air space in February this year.
The commencement of flight operation between Islamabad and Kuala Lumpur has been widely welcomed by business community and travelers.
PIA CEO Air Marshal Arshad Malik in his message on the commencement of Kuala Lumpur flights said that PIA plans to operate more flights on this route based on commercial viability and demand prospects.
He instructed PIA officials to provide best services to passengers.