STORY: Polls predict that Karins' center-right New Unity party will win the election, enabling him to continue his coalition with the conservative National Alliance.
“Everything is in the hands of the electorate right now," said Karins in Sigulda, after casting his vote.
"I’m ready to continue being the Prime Minister if that’s what the people say," he added.
Raivis Dzintars, the chairman of the National Alliance was also seen casting his vote in Sigulda.
A victory for Karins could widen a growing rift between the Latvian majority and Latvia's Russian-speaking minority over their place in society.
The first Latvian head of government to survive a full four-year term, Karins is benefitting from driving the country's hawkish stance against Russia, its amid widespread national anger over Moscow's invasion of Ukraine.
The campaign has been dominated by questions of national identity and security concerns, while urgent issues including soaring energy costs and high inflation were largely pushed aside.
The social democrat Harmony party, traditionally backed by Latvia's Russian-speaking minority, received 19.8% of votes in the 2018 elections and became the largest opposition party in parliament. However, the latest survey indicates 7.3% support for Harmony.