People were queuing at polling stations before the voting began at 7 AM amid tight security to elect the 288-member Maharashtra Assembly.
Among the early voters were NCP's Ajit Pawar, former deputy chief minister, MP Supriya Sule and Pratibha Pawar in Baramati, Leader of Opposition in Legislative Council Vinod Tawde in Mumbai and BJP's Pankaja Munde in Beed, where by-election is also being held for Lok Sabha seat following the death of her father Gopinath Munde in a road accident.
Among Bollywood celebrities Rekha and Abhishek Bachchan cast their votes in the morning.
4,119 candidates are in the electoral fray, including to 276 women in the state with 8.35 crore voters eligible to exercise their right to franchise.
Nearly seven per cent turnout was recorded till 10 AM in Haryana, according to the state's Chief Electoral Officer, Shrikant Walgad. 1,351 candidates, including 116 women, are contesting on 90 seats in the state. The state has over 1.63 crore voters, including 87.37 lakh women.
Chief Minister Bhupinder Singh Hooda was among the prominent people who cast their vote early this morning.
Voting will continue till 6 PM. Counting of votes is on October 19.
The riveting contest in the two states is being seen as the first major test of Prime Minister Narendra Modi's popularity after the Lok Sabha polls and he had spearheaded the BJP campaign in both the states.
Maharashtra's established political formations – Shiv Sena-BJP and Cong-NCP -- split ahead of the polls and the parties are contesting alone after 15 years. Congress and NCP had ruled the state for 15 years from 1999.
In Haryana too, the BJP junked its allies and is hoping to get majority on its own to dislodge Congress that has been ruling the state for the last 10 years.