The latest projections from bookies predict a dead heat between the Czech presidential candidates with the bookies slightly favouriting pro-Russian political veteran Milos Zeman, 73, to win.
Polling stations in the Czech Republic closed at 1pm GMT today and the results are expected to come in at 3pm GMT time.
The election is being viewed as a major political crossroads for the country with both Mr Zeman, and science academic Mr Drahos, 68, being at odds over key issues – including whether or not to stay in the EU.
Populist Mr Zeman is a former centre-left prime minister who has veered sharply to the right.
He takes a tough stance on immigration and has led calls against accepting migrants from mainly Muslim countries – something which the Czech public broadly supports.
He has also called for sanctions to end against Russia over its annexation of Crimea.
Mr Drahos, who was four percentage points ahead of Mr Zeman at the last official poll on Monday, is more of a moderate and is popular with liberal voters.
A win for him may see an attempt at securing stronger relations with the EU, setting the Czech Republic apart from its ex-communist peers Poland and Hungary.
Political analyst Michael Romancov said: “Zeman never questioned the Czech membership in the EU, but on the other hand he said he would welcome a referendum on exit and in practice he significantly deviated from both EU and NATO.”
“It is clear that Jiri Drahos is unequivocally pro-EU and an euro-Atlantic candidate.”
Another analyst Jiri Pehe, said the Czech election is mirroring the sharp divisions between left and right that have featured in other political elections in the US and Europe.
He said: “Society is now really divided 50-50, and it depends which voters are going to come and vote,” adding young, urban voters would benefit Drahos.
A final poll on Monday showed that while Mr Drahos led with 47 percent to 43 percent for Mr Zeman, 10 percent of voters remained undecided.
The winner will serve as president for five years.
Although the role is largely ceremonial, the president does choose which politician can form a government.
Mr Zeman has the backing of Prime Minister Andrej Babis, a billionaire businessman who rules in caretaker capacity after his minority cabinet lost a confidence vote in parliament last week.