ROME — As Italian voters head to the polls on Sunday and Monday to elect a new Parliament and three regional governments, the prevailing mood is one of anger and disillusionment.

The fledgling, anti-establishment parties that campaigned on promises of radical change could benefit from the voters’ discontent, but the lack of a clear winner could also leave Italy mired in uncertainty.

“Italians feel frustration, anger, but also some hope for renewal,” said Nicola Piepoli, who runs a polling company. They are frustrated, he said, because their taxes are rising but they see no improvements in their “economic and social life,” and they are angry because candidates did not address “concrete problems” during the campaign, focusing instead on “futile, absurd things.”

“But many still hope for some change,” Mr. Piepoli added, explaining the growing support for populists like the comedian Beppe Grillo and his Five Star Movement, and for smaller parties like Civil Revolution, led by Antonio Ingroia, a former prosecutor, and Act to Stop the Decline, a movement guided by Oscar Giannino, a journalist.