Justice Mian Saqib Nisar took oath of office as Pakistan's 25th Chief Justice on Saturday.
Nisar, 62, replaced Justice Anwar Zaheer Jamali who retired on Friday after superannuation.
The oath-taking ceremony held in the President House called "Awan-e-Sadr" was attended by Prime Minister Nawaz Sharif, shairman of the Senate, speaker of the National Assembly, federal ministers, services chiefs, parliamentarians, diplomats and judges.
Pakistan's President Mamnoon Hussain administered oath to the new Chief Justice of Supreme Court.
Hussain appointed Nisar as the country's top judge on December 7 ahead of retirement of Jamali who served as chief justice for 15 months since his appointment in September 2015.
Nisar is the senior-most judge and in April this year he served as acting CJ in the absence of Chief Justice Jamali who had gone abroad.
Nisar was appointed as a Supreme Court judge on February 18, 2010. He was serving as judge of the Lahore High Court. He was senior lawyer before elevation the post of judge of the high court and remained member of the Supreme Court Bar Association and Lahore High Court Bar Association (LHCBA).