The economy, slowing towards stagnation, is the main challenge for the next prime minister.
But his ability to carry out change the system may depend on a complex election law that will make it hard to win a clear majority in the upper house of parliament.
Berlusconi, who is seeking a third term as prime minister, and Veltroni have both promised modest tax cuts aimed at spurring consumption.
They have also said that Italy needs more police to tackle crime.Berlusconi advantage
Berlusconi has led opinion polls by between six and nine percentage points but the outcome of the parliamentary election could be close, with up to one third of the 47.3 million electorate expected to make up their minds at the last minute.
However, the last permitted surveys were carried out two weeks ago.
Italy's economy is suffering due to poor domestic demand and the strong euro making exports more costly.
The economic malaise was reflected by the failure to sell the state's controlling stake in airline Alitalia, a major issue for the new government.
In addition, Italy's debt is the world's third highest in absolute terms.
However, voters appeared pessimistic about any new government's ability to solve the problems.
"I wasn't going to vote at first, but my girlfriend kept telling me I should," Flavio Rossi, a Milan waiter, told Reuters news agency.
"My father hasn't voted since 1990. Italy needs a complete makeover and none of them are capable."
He said he would wait until he arrived at the polling booth to decide how to vote.
Al Jazeera's Claudio Lavanga, reporting from Rome, said that Berlusconi and Veltroni have intensely campaigned to tell Italians they have the solutions to the economic downturn.
He said: "They are trying to sell the idea that they can turn this country around and bring on the right path."
"However, Veltroni's policy platform is not really that different from Berlusconi's despite his political rhetoric resembling Barack Obama's [US Democratic presidential candidate].Complex system
The voting system put in place by Berlusconi's last government, before he narrowly lost a 2006 election to Romano Prodi, make is it difficult to win a strong majority in the Senate, the upper house of parliament.
|Veltroni has attacked Berlusconi's fondness |
for jokes saying he is "not a statesman" [AFP]
The election winner will probably have to form a coalition government with one of several small parties, which have largely been kept at arms length by the main candidates during campaigning.
The next prime minister will want as strong a coalition as possible to avoid the fate of Prodi's government, which collapsed 20 months into a five-year term.
The possibility of a split parliament led Pier Ferdinando Casini, leader of the Union of Christian Democrats (UDC), to say that he could take up the premiership to become a referee between the two large blocs.
Berlusconi has urged supporters of smaller groups - there are a total of 32 candidates for prime minister - to cast a "useful vote" for his People of Freedom (PDL).'Serious country'
Veltroni has attacked Berlusconi's economic record and his fondness for jokes, like making the two-fingered Latin gesture for a cuckold behind the head of a Spanish minister in 2002.
"Italy is a serious country and doesn't need a premier who sticks up his fingers or tells dirty jokes at European summits," Veltroni said on the last day of campaigning.
"He's not a statesman. That's what all the international papers say."
Veltroni quoted the Organisation for Economic Co-operation and Development as saying that "in the five years from 2001-2006 [when Berlusconi was in office] Italy was at a standstill".
Berlusconi for his part has accused Veltroni of having run "a campaign of lies", in television appearances on Friday he accused him of lying 43 times in a single interview.