He is representing Imo West Senatorial District of the state.
Nelson Ayewoh, clerk to the Senate, was in charge of the swearing.
Okorocha signed all the mandatory documents after the swearing in.
Two days ago Okorocha was not among the senators sworn into office when the senate was inaugurated.
Okorocha was issued with his certificate of return after a court order on Tuesday.
The Independent National Electoral Commission (INEC) revealing this yesterday.
Earlier on, INEC had refused to recognize Okorocha as the winner at the poll.
He was formerly alleged that is victory was unlawfully secured.Do you want to be the first to get these news,updates and vital info?