The last time Thailand tried to hold an election in 2014, it ended with a military coup.
An army general took over as prime minister and promised to hold a new election.
It has taken five years for people to be given the chance to vote.
At east 92,000 polling stations opened across Thailand on Sunday.
Prime Minister Prayuth Chan-ocha wants to remain in office.
He faces a strong challenge from Pheu Thai, the most prominent anti-military-government party linked to former leader Thaksin Shinawatra.
Six million young people are casting their ballot for the first time. And since the coup, numerous new parties have sprung up to court their votes.
But how democratic is the election?
Presenter: Nick Clark
Sunai Phasuk – senior Thailand researcher at Human Rights Watch
Michael Montesano – senior fellow and coordinator of the Thailand Studies programme at Singapore’s ISEAS Yusof-Ishak Institute
Pavida Pananond – economist and professor of international business at the Thammasat Business School
Source: Al Jazeera News