The nine-phase polling that will end May 12 begins with voting in five of 14 Lok Sabha constituencies in Congress-ruled Assam and one of the two in Left-held Tripura in the northeast Monday.
The nationwide vote count will take place May 16.
The massive exercise will involve 814 million electorate, with 120-150 million first-time voters, hundreds of candidates -- nominations are still being filed -- and dozens of political parties all over the country.
A political pundit Sunday hailed the once-in-five-years parliamentary battle.
"Any election that India has seen has been an important exercise because nowhere so many people go out and vote together," political expert Mridula Mukherjee told IANS.
"It is a significant event in democratic experiment because all the elections have seen power being handed over from one hand to another, and smoothly," the academic said.
Although fingers are still crossed on whether the BJP-led National Democratic Alliance (NDA) will secure a majority in the 545-member Lok Sabha, the Congress and its shrunken United Progressive Alliance (UPA) which has ruled India since 2004 look bruised.
Exploiting popular disgust vis-a-vis the Congress-led government, BJP's prime ministerial candidate and Hindutva icon Narendra Modi has been leading his party's charge asking people to elect at least 300 MPs from his coalition.
Ranged against both the UPA and NDA are regional parties with devoted pockets of support such as the Samajwadi Party and the Bahujan Samaj Party (Uttar Pradesh), Biju Janata Dal (Orissa), the DMK and AIADMK (Tamil Nadu), the Trinamool Congress (West Bengal) and the Janata Dal-United and the Rashtriya Janata Dal (Bihar). All of them could play a major role in the event of another hung parliament.
The Bharatiya Janata Party is supremely confident. "We are very sure the BJP will alone get up to 250 seats," its spokesman Prakash Javadekar told IANS. He felt the NDA tally might touch "290 or so".
Any party or coalition will need 272 seats to form a government.
The Congress feels that pollsters predicting its defeat will be proved wrong again -- as it happened in the 2004 and 2009 elections.
"The UPA will surprise everyone," spokesperson Abhishek Singhvi told IANS. "With our known allies and a few others, we will easily form the government."
Analyst Mukherjee pointed out that one key factor in this election was the Aam Aadmi Party (AAP) -- which is ranged against everyone else.
"It is a new political phenomenon where an anti-corruption movement has become a party," she said. "It is a party with a different background with all kinds of people in it."
The AAP, which ruled Delhi for 49 days until Feb 14, has pitted its leader Arvind Kejriwal against Modi in Varanasi in Uttar Pradesh.
Political analyst Pradip Dutta admitted that the BJP had a much larger lead over the Congress but added that he does not see "a Modi wave" talked about in the media.
"The BJP should not take its victory for granted," Dutta told IANS.
Another political analyst, Badri Narayan Tiwari, added: "The BJP won't get a clear majority."
Since he was made head of the BJP election campaign, Modi, still the Gujarat chief minister, has grown and grown, becoming the main focus point in the election.
The 63-year-old has hoisted his aggressive persona on a party which for decades believed in collective leadership. He has attempted to give up his Hindu hardliner image without giving up Hindutva politics.