This year’s memorial is intended to be the last public acknowledgement of Australia's worst mass murder.
Prime Minister John Howard will attend the ceremony at Port Arthur with acting Governor-General Marie Bashir and Tasmanian Premier Paul Lennon also expected to join the service.
On April 28, 1996, Hobart man Martin Bryant went on a shooting spree at Port Arthur, a convict prison ruins in Tasmania's south-east, killing 35 people.
He is currently serving a life sentence without parole in Hobart's Risdon Prison for the murders.
Memorials questioned
There has been concern voiced by welfare advocates and psychologists that the commemorations of the massacre could be harmful to the survivors and the victims' families.
Mr Howard has disagreed and said it was vital that a memorial service be held to help individuals and communities cope with their continuing grief.
"I respect the fact that people will have a range of views, but I think it is important that there be some occasion," Mr Howard told journalists Thursday.
"Clearly for the relatives of people who were murdered it will be terrible, and I guess that reluctance (to remember) is born of continuing disbelief that it could happen in such a protected, remote and lovely part of Australia," he said.
Hobart clinical psychologist Dr Harry Stanton has told the ABC that the Prime Minister's presence would merely draw unwanted attention to an event that the victims would rather put behind them.
"What it's doing is raising the whole image of the thing. It's lifting it to a new level and I really don't think that's appropriate," Dr Stanton said.
Gun debate
At the time of the massacre, Mr Howard had been prime minister for less than two months and after the shootings he swiftly tightened gun laws, a move he said he had long wanted to do.
What followed was a massive buyback of Australian firearms in which more than 700,000 guns were purchased by the Government and destroyed.
The massacre turned out to be an event which defined his first year in office.
"I saw in Port Arthur an opportunity to use the authority of this office in a tragedy to do some good," Mr Howard said.
Tasmanian Labor MP and former federal justice minister Duncan Kerr said governments should have a fresh look at handguns.
Mr Kerr said handguns were largely overlooked after the Port Arthur massacre because it was felt they were already tightly controlled.
"If we were starting again we would probably have a much tougher regime for handguns," Mr Kerr told AAP. “Police continue to be concerned about the possibility of concealed weapons," he said.