Speaker Ayaz Sadiq, who defeated him in Lahore, administered oath to Imran Khan, who is the last one to take oath.
He had been on bed rest following a terrible incident in a Lahore rally during election blitz leaving his back and head injured.
Doctors had prohibited him to travel and work physically. However, last week he was allowed to travel and he traveled to the capital city of Islamabad on a private plane.
Khan had not taken oath as member of the national assembly even after winning three seats of the national assembly from Mianwali, Peshawar and Rawalpindi. He has taken oath as the member keeping his Rawalpindi seat intact.