The elections are seen as a test for coexistence in a nation where sectarian resentment continues 20 years after the end of a 1975-1990 civil war.
Nearly 767,000 people are eligible to vote in the north, for 238 town councils and 646 mukhtars or mayors, with another 112 councils in the region having already been elected to office based on family and clan affiliations.
In the Sunni areas, notably Tripoli, Prime Minister Saad Hariri's list of candidates was easily expected to secure the most votes.
In Christian areas like Zghorta, Koura and Batroun, a close contest was predicted, between Christian MP Michel Aoun -- an ally of Hezbollah -- and Christian leader Samir Geagea who is a member of Hariri's ruling coalition.
Polling stations opened at 7:00 a.m. (0400 GMT) and are due to close at 7:00 p.m. (1600 GMT).
Concerns of violence were heightened after a family dispute that turned political deteriorated into a gunfight that killed two people Friday in the town of Dahr El-Ain in the northern Koura district.
Voting among Lebanon's 3.33 million electorate began on May 2 in the Mount Lebanon area overlooking the capital, with voters casting their ballots every Sunday this month except May 16.
Thousands of security and military personnel have been deployed to ensure the safety of the polls, in which a simple majority is needed for victory.
The last local elections were in 2004.
A political lull reigns in Lebanon since the formation in November last year of a national unity government, which includes two Hezbollah ministers.
Municipal elections in Lebanon are held every six years.
