Chandy said after casting his vote that he was confident the Congress-led United Democratic Front (UDF) would retain its majority in the 140-member assembly.
"We are certain the people will give us one more chance," Chandy told the media at his hometown Puthupally near here.
Polling began at 7.00 am across the state and will end at 6.00 p.m. The main opponent to the UDF is the Left Democratic Front (LDF) led by the Communist Party of India-Marxist.
Congress leader and former chief minister A.K. Antony: "For the first time in the state a ruling party is going to retain power. While the Left will remain in the opposition, the BJP won't win any seat."
Marxist leader Achuthanandan, contesting from Malampuzha in Palakkad district, met voters one last time before returning to Alappuzha to cast his vote.
"There is a slight rain and this is a good omen," he said. "There is a huge wave in our favour. We are heading for a landslide victory.
"People are going to show the exit door to Chandy," he added.
The Bharatiya Janata Party (BJP) is hoping to enter the Kerala assembly for the first time.
State BJP president Kummanem Rajasekheran, contesting in Vatiyoorkavu in the heart of the state capital, said that looking at the voter turnout, things were looking very bright for the BJP.
"There is a strong opposition to both the Left and the Congress. That's why we are hugely confident this time," he said.