Opinion polls show him holding a slim lead with about 33 per cent support, compared with 30 per cent for his left-wing challenger, Mircea Geoana. The third candidate, Crin Antonescu, has about 18 per cent backing.
A second round of voting between the top two candidates will take place on December 6 if no one wins an absolute majority.
The centre-left coalition government collapsed last month, just weeks before the election, as a result of party feuding. The new president is expected to appoint a prime minister to form a new cabinet.
IMF interest
Its main task will be to win back the trust of international lenders, including the International Monetary Fund and the European Commission, and restore investor confidence damaged by political instability and back-pedalling on reforms.
Rodica Pricop, editor in chief of the Nine O'Clock newspaper, told Al Jazeera that Romania is currently the most corrupt country in the European Union.
"This is why the World Bank and the European Commission need a new government to discuss loan schedules and repayments .... though Romania is probably going to apply of a new loan in March next year", Pricop said.
With the presidential vote too close to call, what kind of government will emerge is unclear. Whoever forms it will have three election-free years to overhaul bloated public finances and clear out a political class steeped in murky deals and graft.
Broad reforms are vital. Twenty years after the end of communist rule, Romania, a Balkan country of 22 million people, remains one of the poorest and most corruption-prone corners of the European Union.
In the short-term, mending relations with the IMF will be vital to restore payments from Romania's 20 billion euro aid package led by the Fund earlier this year, and to ensure the economy moves smoothly out of recession.
This will require passing a sound budget plan for 2010 and making further cuts in public spending, particularly difficult ahead of the election.