Newly-elected MNAs took oath in the inaugural session of the 15th National Assembly on Monday.
The swearing-in marked the third consecutive democratic transfer of power in the country.
Outgoing National Assembly speaker Sardar Ayaz Sadiq administered oath to the newly-elected members. This was followed by signing of the 'Roll of Members'.
Pakistan Tehreek-e-Insaf (PTI) chairman Imran Khan, who is set to become the country's next prime minister, also took the oath.
Other leaders of prominent political parties including PPP's Bilawal Bhutto Zardari and Asif Zardari, and PML-N president Shehbaz Sharif were also in attendance. Bilawal, who has been elected to the National Assembly for the first time, shook hands with Imran Khan as the MNA-elects took their seats.
The first sessions of the new Sindh, Khyber Pakhtunkhwa (KP), and Balochistan assemblies are also being convened today. The Punjab Assembly session, on the other hand, is slated for August 15 after the Independence Day.
Elections for Speaker and Deputy Speaker of the National Assembly will be held on August 15.
Earlier, President Mamnoon Hussain approved the National Assembly's first session for August 13 on the request of caretaker Prime Minister Justice (retired) Nasir-ul-Mulk.