Hometown contenders Donald Trump and Hillary Clinton are favoured to sweep the state for their parties.
But they're both struggling to shake off their rivals in the race for the White House.
As she prepared to receive the verdict from her home state, Hillary Clinton went back to one of the most controversial issues to dominate the campaign - immigration and race.
"There are a lot of differences between me and my opponents, both in the Democratic primary and in the Republican primary. And I can tell you this, I will not let someone like Donald Trump or Ted Cruz say what he is saying about the people, the hardworking people, including immigrants, but everyone who works hard in New York." And contrary to Senator Cruz, I think New York values are America's values, and we want to stand up for those here in New York and across the country."
On the streets of the Big Apple, opinion among Democrats was divided between the party frontrunner and the rival she just can't shake off: Bernie Sanders.
None is more torn than voter Marguerite Stimpson.
"I love Bernie's platforms, I'm just not sure realistically if they can be applied nationwide and I've always been a fan of Hillary's so I'm just very torn. I'll probably decide the moment I walk in to vote."
Aerie Fuentes, meanwhile, is in no doubt as to who will be the contestants in the ultimate White House battle.
"The fight is definitely between Trump and Hillary, they're like neck and neck, like you could see the fists."
But with the polls narrowing in New York, it's not an inevitability that Bernie Sanders was prepared to accept as he campaigned in the lead-up to the vote.
He was busy targeting Hillary Clinton over the hefty fees she received in government for speaking to Wall Street bankers.
At a rally in Pennsylvania, Mr Sanders dramatically produced thin-air with his hands to show the number of times he had taken money for speeches.
"I will release all of the transcripts of all of the speeches that I have given before Wall Street. In order to be a 100 per cent transparent I am going to toss them out to you. Are you ready? Shoosh...you got 'em? I don't need $225,000, I don't need two dollars, I don't need two cents."
Another outsider - but on the Republican side - is also unwilling to give up the fight, despite billionaire businessman Donald Trump and Texas Senator Ted Cruz remaining the main contenders for the GOP nomination.
Ohio Governor John Kasich has his eyes firmly on the party convention in July.
"It's all about accumulating delegates going into the convention and we are actually going to have a competitive convention. Some people will say, 'well. shouldn't the guy who has the plurality or whatever, be the one that gets picked, well look, we have rules, and if you don't hit the magic number then you don't get enough. Yesterday CBS came out with another poll and again, I am the only one that beats Hillary, beats her by twelve points."
It is all about the numbers but John Kasich and Ted Cruz know victory in New York will give Donald Trump's campaign crucial renewed momentum in the race for the White House, even if he's yet to reach that clear majority of at least 1,237 delegates.
For both Donald Trump and Hilary Clinton in the Big Apple, it's about winning .... and about winning big.
