Sunday’s election could decide whether the former Soviet nation moves towards the EU or turns back to Russia.
Thousands have protested against Moldova’s government, saying it has failed to implement reforms to bring the country closer to the European Union.
Protesters also called on the government on Sunday to investigate the disappearance of $1.5b last year from the state-owned Savings Bank, and the private banks Unibank and the Social Bank.
The funds went missing in November, before general elections.
Demonstrators marched in the capital Chisinau, waving Moldovan and EU flags while yelling “Down with the thieves” and “We want the billions back”.
Moldovan officials have recently launched an investigation into the disappearance of the funds.
Moldova’s currency has lost 20 percent value this year, which could severely worsen the country’s already poor economy.
Moldova signed an association agreement with the EU last year. But the current government is backed by communists, who favor a slower approach to reforms.