The former senator announced his decision during a meeting the PML-N chief Mian Nawaz Sharif.
Raisani had resigned from PPP in 2012 after he developed differences with the party. He developed considerable clout in the province as the brother of the former chief minister Nawab Aslam Raisani and in his own right as a PPP leader there.
Raisani announced to join the PML-N along with his 21 associates. Raisani, younger brother of Brahvi tribal chief, has served in the past as a member of the Provincial Assembly of Balochistan for the PPP.
Around 22-members includes Lashkari Raisani, Humayun Kurd, Tahir Mehmood, Ismail Gujer and Chaudhry Rafat and others.
Sources said that the Baloch leaders discussed the current political and deteriorating law and order situation with the PML-N leader.
Nawaz told the delegation that only Baloch leadership could resolve the problems of the province. He criticised the situation and genocide of Shia community in Karachi and Quetta.
The former PPP leader resigned from Senate in 2012.