Rebranding itself as a moderate "conservative people's party", its leader Gabor Vona has called for a change in government and railed against Mr Orban.
"As long as the opposition is in a fragmented state. this migrant/refugee campaign is sufficient to keep (Orban's) voting base united, to keep it mobilized", said Balazs Bocskei, political analyst at the Idea Institute, a Budapest think-tank.
By focussing its attacks on corruption and cronyism, and highlighting the need to tackle social inequality in Hungary, Jobbik has struck a chord with disaffected Hungarians. "Emigration may or may not define Hungary, and I would prefer that it does not".
Orban himself voted early on Sunday morning with his wife at a school in the leafy Zugliget suburb of Budapest.
High turnout may ultimately also hurt smaller opposition parties, because it would raise the number of votes needed to reach the 5 percent threshold to get into parliament.
USAF Thunderbird F-16 crash kills pilot
Tuesday afternoon, a Marine helicopter went down in Southern California, presumably killing all four crew members onboard. It was later determined that the F-16, which the pilot safely ejected from, crashed because of an equipment malfunction.
Orban is credited with keeping the budget deficit under control, reducing unemployment and some of Hungary's debt, and putting its economy on a growth track.
Meanwhile Jobbik leader Gabor Vona cast his vote in the north-eastern town of Gyongyos, urging voters to turn out and saying that the result would "determine the fate of Hungary not just for four years but... for two generations".
In Hodmezovasarhely, a Fidesz stronghold in southeastern Hungary, voters complaining of graft, cronyism, and intimidation elected an independent in a February mayoral election for the first time in two decades.
"My little daughter must be my primary concern, to make her future safe". She would not reveal her voting preference.
In March the government also gave pre-election handouts to millions of families and pensioners.
Vehicle ploughs pedestrians in Munster, Germany; several dead, multiple injured
Police have urged people in Muenster to stay inside their homes and avoid the crash scene in the city's historic downtown. Amri was shot dead by Italian police in Milan four days later after travelling through several European countries.
The centre-left Socialists meanwhile were on 14% in Friday's poll and not thought to pose a threat to Fidesz. Voter turnout was estimated between 64 and 68 percent.
However, one-third of voters remain undecided, and an upset is not being ruled out.
"Today the freedom, sovereignty and dignity of nations, for you and for us Poles, is tied to Viktor Orban", he said.
Hungarian election officials say voter turnout in the country's parliamentary election 90 minutes before polls close has already exceeded the total turnout for the 2014 elections.
Prime Minister Viktor Orban's Fidesz party is expected to win the majority of the 199 parliamentary seats, with Vona's Jobbik and a left-wing alliance of the Socialist Party and the Dialogue party led by Gergely Karacsony considered the leading challengers. Businessmen close to Fidesz have acquired stakes in major industries like banking, energy, construction and tourism, profiting from European Union funds.
Woman's shocking discovery about father after Ancestry.com DNA test
In the lawsuit, Ms Rowlette claims that the doctor was aware of using his own sperm as a donor, but her mother was never informed. As a result, "people may learn of unexpected connections" unless they choose to make their DNA match settings private.