Here’s a look at the top contests today:
In Uttar Pradesh's Mathura, BJP's Hema Malini is facing sitting MP Jayant Chaudhary of the Rashtriya Lok Dal. Jayant is the son of Union Minister Ajit Singh and grandson of former Prime Minister Charan Singh.
All of Tamil Nadu is voting today. At Sivaganga, Finance Minister P Chidambaram's son, Karti is the Congress candidate. His main rival is PR Senthilnathan of the AIADMK, whose Raja Kannapan had lost by a wafer-thin margin to Mr Chidambaram in the 2009 election. The BJP has fielded H Raja.
Six seats of Mumbai are among 19 Maharashtra constituencies voting today. In Mumbai South, union minister Milind Deora has been challenged by Aam Aadmi Party's Meera Sanyal, who was CEO and chairperson of the Royal Bank of Scotland till 2013.
In Mumbai North Central, the BJP has fielded Poonam Mahajan, daughter of senior party leader Pramod Mahajan, who died after being shot by his brother in 2006. Poonam is challenging Congress MP Priya Dutt, the daughter of late actor-turned-politician Sunil Dutt.
Mumbai North West has an interesting array of candidates. Union minister Gurudas Kamat is facing Aam Aadmi Party's Mayank Gandhi and filmmaker Mahesh Manjrekar from Raj Thackeray's Maharashtra Navnirman Sena (MNS). Another face from the entertainment industry is also contesting here - Rakhi Sawant.
Two brothers are pitted against each other in Rajasthan's Dausa seat. Union minister Namo Narayan Meena of the Congress is facing BJP's Harish Meena, a former Director General of Police.
In Alwar, union minister Jitender Singh of the Congress is fighting for a second term. He faces the BJP's Mahant Chandnath, a disciple of yoga teacher Ramdev.
Six constituencies of West Bengal are going to polls. In Raiganj, another family battle is playing out with the Trinamool Congress choosing Pabitra Ranjan Dasmunsi as its candidate. He is the brother of Congress leader Priya Ranjan Dasmunsi, who has been bedridden for six years and whose wife Deepa Dasmunsi is the Congress candidate.
Two former Chief Ministers of Jharkhand are contesting in the state's Dumka seat - Babulal Marandi of the Jharkhand Vikas Morcha and Shibu Soren of the Jharkhand Mukti Morcha.
In the Guwahati seat, former union minister Bijoya Chakraborty of the BJP is facing another former union minister, Birendra Prasad Baishya, who is the Asom Gana Parishad candidate.