Speaking on the 23rd anniversary of the murder of top anti-Mafia prosecutor Giovanni Falcone, Italian President Sergio Mattarella has pledged his country will finally prevail over organised crime.

"I am here to renew a promise: we will beat the Mafia, we will eliminate it from our society, because it is incompatible with freedom and human co-existence," Mattarella said in Palermo, Sicily's main town, on Saturday.

Palermo was hosting several events to honour Falcone, the man behind major investigative breakthroughs in the 1980s that led to the biggest-ever trial against the Sicilian Mafia, which saw the simultaneous conviction of 360 mobsters.

Mattarella, a Palermo native who saw his brother Piersanti gunned down by the Mafia in 1980, was the keynote speaker at a ceremony inside the special chamber built inside the Ucciardone prison to house the mass trial.

Interior Minister Angelino Alfano and Police Chief Alessandro Pansa laid flowers on the highway spot where Falcone, his wife and three police escorts were killed, while travelling in an armoured car convoy from the airport to downtown Palermo.

The Italian Education Ministry said more than 40,000 students, including about 100 from other European nations and the United States, were slated to take part in various anti-Mafia rallies and marches in Palermo and six other cities.