The Italian government has scheduled national elections for May 13 and says municipal elections would be held the same day.
The widely expected announcement came the day after the end of parliament's five-year term.
Polls say conservative Silvio Berlusconi has a good chance of defeating the centre-left candidate, Francesco Rutelli.
Media baron Mr Berlusconi's well-financed campaign has been under way for months.
The race is attracting attention - and some apprehension - across Europe because of Berlusconi's partners in his conservative coalition. One is the National Alliance, borne from the remains of the wartime Fascist Party.
The other is Northern League leader Umberto Bossi, who harsh attacks on immigration have prompted comparisons to Austria's Joerg Haider.
Mr Berlusconi has had to defend his choice of allies a number of times, both at home and abroad and Rutelli has called it one of his opponent's greatest vulnerabilities.
Mr Rutelli, who is running for national office for the first time, is also trying to turn conflict of interest into a major campaign issue.
One of the richest men in the world, the 64-year-old Mr Berlusconi was premier for eight months in 1994.
Mr Rutelli, 46, was Rome's mayor for seven years, winning high marks for managing the city during a Roman Catholic Holy Year that brought 25 million pilgrims to the city last year.