The stakes in this round are the highest for the ruling Samajwadi Party (SP).
The high-decibel campaign for the 67 seats ended on Monday evening, with political parties pulling out all stops to woo voters.
The SP holds 34 of the 67 seats, the Bahujan Samaj Party (BSP) 17, the BJP 10 and the Congress four. Smaller outfits such as the Peace Party and Ittehadul-E-Millat Council had won one seat each in 2012.
Polling will take place in Sambhal, Moradabad, Rampur, Bareilly, Amroha, Pilibhit, Lakhimpur Kheri, Shahjahanpur, Bijnore, Saharanpur and Budayun districts.
Prime Minister Narendra Modi, Chief Minister Akhilesh Yadav, Congress Vice President Rahul Gandhi and BSP chief Mayawati campaigned extensively for this phase of polls.
The fate of Uttar Pradesh Minister Mohd Adam Khan, his son Abdullah Azam and ministers Iqbal Masood, Haji Riiyaz Ahmad, Mehboob Ali, Ram Moorti Verma, Kamal Akhtar and Mool Chandra Chauhan will be decided on Wednesday.
A total of 720 candidates are in the fray. Of the 2.28 crore voters, 1.23 crore are males. The maximum number of 28 candidates are in Kaanth constituency and the least (5) in Ghanaura.
The staggered battle to pick a 403-seat Uttar Pradesh assembly began on February 11 when 73 constituencies went to the polls.