Brenton Harrison Tarrant, 28, appeared by video link at the High Court in Christchurch this morning, where his not guilty pleas were entered.
Tarrant appeared before Justice Mander in the High Court at Christchurch just after 9am.
He appeared to smile as one of his lawyers entered the not guilty pleas on his behalf.
He has denied 51 charges of murder, 40 charges of attempted murder and one terrorism charge through his lawyers.
The pleas were met with quiet gasps from the victims and their families, who packed the public gallery in the back of the courtroom.
About 80 people, who sat behind senior police officers in court, were still and quiet for the remainder of the hearing.
Justice Mander set a trial date of 4 May next year.
At this stage the Crown estimates it will take six weeks.
The accused will next appear for a case-review hearing in August.
Tarrant first appeared in Christchurch District Court the day after the mosque attacks on 15 March, where he was charged with multiple counts of murder.
After his first appearance in court, police later laid an additional murder charge, two additional attempted murder charges and the terrorism charge.
The charge - laid after consultation between police, Crown Law and the Christchurch Crown Solicitor's Office - alleges a terrorist act was carried out on 15 March.
Major New Zealand news organisations, including RNZ, have agreed to protocols for covering the trial of the person charged for the Christchurch mosque attacks.
Today is the first time RNZ has published an unpixelated court photograph of the accused gunman's face.
Media applications to film and photograph the defendant were granted at his first court appearance on the basis the man's face was blurred but this suppression order lapsed last week.
This article was first published on Radio NZ.