The peso actually dropped to 800 during the day, well beyond the previous record of 761, from October 10, 2002, before recovering slightly at close.
It had closed on Monday night at 760 to the dollar.
The peso has been hit hard by nearly four weeks of protests against the economic policies of right-wing President Sebastian Pinera.
It was trading at 709 to the dollar on October 18 when the protests erupted into violence.
"It's a sign of concern that we're looking at closely," said Finance Minister Ignacio Briones.
The peso's fall came as 80,000 people took to the streets of the capital Santiago with more than 100 organizations calling for a general strike.
The demonstrators are demanding greater social reform from Pinera, who has announced several measures in a bid to appease protesters.
"Everything the president has offered is insufficient. It's a joke," Karen Delgado, a 29-year-old office worker, said.
Briones said the currency fluctuation would "have an impact on prices, inflation and the entire portfolio of goods we consume."
The Santiago stock exchange fell 1.57 percent, recovering slightly after having dropped 3.38 percent by midday.
In a statement, the central bank said the peso's drop was "expected in the context of the greater uncertainty that we're seeing."
Analysts Capital Economics said the peso's fall and Tuesday's strikes would "push up inflation" and predicted that sustained unrest would weaken growth, which it said would be lower than its previously downgraded prediction of 2.5 percent.