—Proceeding pursuant to CPLR article 78 (transferred to this Court by order of the Supreme Court, entered in Albany County) to review a determination of respondent which found petitioner guilty of violating certain prison disciplinary rules.
Petitioner was an inmate at Washington Correctional Facility in Washington County when he was found guilty of assault on an inmate and possession of a weapon in violation of prison disciplinary rules. Two separate misbehavior reports were filed against petitioner. The first report was authored by a correction officer who witnessed petitioner repeatedly striking a fellow inmate in the face and chest, leaving the inmate with puncture wounds and lácerations on his chest, right arm and hand. The second report was written by a civilian staff member who, immediately following petitioner’s assault on the inmate, saw petitioner make a throwing motion toward an area where a sharpened metal rod later was found.
*699Petitioner contends that the determination of his guilt was not based upon substantial evidence. We disagree. Adduced in evidence against petitioner were two misbehavior reports authored by individuals who were eyewitnesses to the events in question and who testified at the hearing, giving detailed descriptions of petitioner’s misconduct. While petitioner presented his own exculpatory testimony, as well as that of his fellow inmates, such testimony merely presented a question of credibility, which was appropriately determined by the Hearing Officer (see, Matter of Foster v Coughlin, 76 NY2d 964, 966; Matter of Jimenez v Coughlin, 206 AD2d 769, 770).
Petitioner’s contentions regarding certain alleged irregularities in the misbehavior reports are unavailing in that he has failed to show that any prejudice has resulted therefrom (see, Matter of Rivera v Keane, 225 AD2d 699). We have examined petitioner’s remaining contentions and find them to be either without merit or unpreserved for review by this Court.
Cardona, P. J., Mikoll, Crew III, White and Peters, JJ., concur. Adjudged that the determination is confirmed, without costs, and petition dismissed.