Voters were still queued up at polling stations and the poll percentage would go up, officials said.
The balloting will decide the fate of 1,351 candidates, including 116 women.
The BJP, which is contesting the assembly polls in the state on its own for the first time, was upbeat about the high turnout so far, saying that the voters wanted a change.
"The BJP is all set to form the next government in Haryana on its own. We will get a clear majority and end the rule of scams and corruption," BJP leader Abhimanyu said.
However, incumbent Chief Minister Bhupinder Singh Hooda, who cast his vote in his native village, was not willing to give up easily.
"Seeing the response of the voters, I can say that the Congress will win the elections and form the government for a third term," Hooda said.
The opposition Indian National Lok Dal (INLD) said that the heavy turnout was an indicator that the party (INLD) was going to form the next government in the state.
"We will form the next government," INLD leader Abhay Chautala said.
Minor clashes were reported at four places between workers of the Indian National Lok Dal (INLD), Bharatiya Janata Party and others.
A clash took place between BJP and INLD workers in Baansgaon of Narnaund assembly constituency in Hisar district. BJP candidate Abhimanyu alleged that INLD workers captured the polling booth and stopped the webcast from there.
In Sirsa district, an incident of firing was reported from Modiakhera village. Another clash was reported from Punhana area in south Haryana.
Voting was impacted in Sikanderpur village in Pataudi constituency as an official told women to unveil their faces before voting, police said.
The voting will officially continue till 6 p.m. but all those queuing up by then would be allowed to cast their votes, the officials said.
About 40 percent polling was reported from Haryana till 1 p.m.
Kurukshetra, Yamunanagar, Mewat, Fatehabad, Kaithal, Jind, Sirsa and Palwal districts led with 65 to nearly 70 percent voting till 3.30 p.m.
The NCR areas of Faridabad and Gurgaon recorded a relatively lower turnout of 49 and 55 percent respectively.
Among the early voters Wednesday were the country's richest woman Savitri Jindal, INLD candidates Naina Chautala and Dushyant Chautala, who is the Hisar MP, Haryana Janhit Congress (HJC) president Kuldeep Bishnoi, union Minister of State Krishan Pal Gurjar and former union minister Venod Sharma.
Heavy ballotting was reported from majority of the booths. Voters patiently stood outside rural polling stations in most areas. At many urban polling booths also, brisk voting was reported.
Voters could be seen queued up at some polling stations even before the official start time of 7 a.m. Women voters were also seen lining up enthusiastically, especially in rural areas.
Polling across the state was held at 16,357 polling centres between 7 a.m. and 6 p.m.
The main contest is between the ruling Congress, the main opposition Indian National Lok Dal (INLD) and the Bharatiya Janata Party (BJP).
Most seats are witnessing multi-cornered contests this time with other parties like Haryana Janhit Congress (HJC), the newly floated Haryana Jan Chetna Party (HJCP), Haryana Lokhit Party (HLP) and the Bahujan Samaj Party (BSP) also being in the fray.