On Sunday two pollsters revealed that Milatovic, the 37-year-old deputy head of the Europe Now movement, has secured 60.1% votes in a race against incumbent Milo Djukanovic, a 61-year-old former communist.
Djukanovic, who was in power for 33 years following the collapse of federal Yugoslavia, secured 39.9% of votes, according to the Podgorica-based Center for Monitoring and Research (CEMI) pollster.
"I congratulate the new president Jakov Milatovic," said Ana Nenezic, the executive director of the Center for Monitoring and Research.
According to CEMI, voter turnout stood at 70%. The official results of the election are expected to be announced in the coming days.
If elected, Montenegro's president, who stays in office for a five-year-term, will have a primarily ceremonial role. The Balkan nation is also facing parliamentary elections, following months of gridlock since the government collapsed in August due to a no-confidence vote.