Islamabad: Imran Khan, Pakistan's cricket legend, took oath as the 22nd Prime Minister of Pakistan on Saturday.
The swearing-in came a day after Imran Khan won the backing from the newly-elected Parliament.
Imran Khan, 65, who won a simple majority from lawmakers on Friday in a confidence vote was administered oath by President Mamnoon Hussain.
Imran Khan has been sworn-in as the PM three weeks after the general elections took place on July 25.
He outvoted opposition and PML-N prime ministerial candidate Shahbaz Sharif in the PM's election.
Imran Khan's wife Bushra Maneka was also present at his oath-taking ceremony in Islamabad.
On Friday, in his first address to Parliament, Imran Khan vowed to act against those who looted Pakistan. "I promise my nation today that we will bring the tabdeeli (change) that this nation was starving for," Imran Khan.
"We have to hold strict accountability in this country; the people who looted this country, I promise that I will work against them," he vowed.
The Oxford-educated Pasthun, who launched Tehreek-e-Insaf, which means the movement for justice, in 1996, said that he reached this place after struggling for 22 years.
Former Indian cricket star Navjot Singh Sidhu is also among the special guests invited by Imran Khan's team to attend the ceremony.
Imran Khan, who famously captained the national cricket team to World Cup glory in 1992, has also invited some of his former teammates to witness his formal ascension to the top ministerial job in the country.
The Pakistan Tehreek-e-Insaf emerged as the single largest party with 116 seats in July 25 elections. Its number increased to 125 after nine independent members joined it and final tally reached 158 after it was allotted 28 out of 60 seats reserved for women and five out of 10 seats reserved for minorities.
Imran Khan's government will be the third consecutive democratic government in Pakistan since 2008 when military ruler Gen Pervez Musharraf announced elections after serving as president from 2001 to 2008 following a bloodless coup in 1999.
The Pakistan Peoples Party formed the government in 2008, followed by the Pakistan Muslim League-Nawaz led by jailed former prime minister Nawaz Sharif in 2013.
Pakistan's powerful military has ruled the country through various coups for nearly half of the country's history since independence in 1947.