Police say a 34-year-old inmate attacked his female lawyer at his parole hearing at Halawa Correctional Facility on Monday.
The inmate is serving a 10-year prison term for second-degree robbery.
The hearing had concluded and the inmate and lawyer were leaving the hearing room when he punched the lawyer in the face and kicked her, police said.
Prison officials were able to restrain him. The lawyer was taken to a hospital in fair condition.
The lawyer, a state deputy public defender, went to Halawa to appear with him in front of the Hawaii Paroling Authority for a hearing to establish how much of his 10-year sentence the inmate must serve behind bars before he can ask for parole.
Police are investigating the case as a misdemeanor assault.