Mr Zeman, who previously served as prime minister from 1998 to 2002, is currently the favourite to win out of the nine candidates standing.
The renowned Eurosceptic has fiercely criticised immigration from Muslim-majority countries – a viewpoint that appears to chime with many voters.
He is also believed to be Russia’s favoured candidate and the 73-year-old has met frequently with Vladimir Putin.
Mr Zeman has also supported the lifting of sanctions against Moscow and called for the recognition of Crimea.
And the election is now facing concerns it could become the subject of Russian meddling.
Russia has already been accused of trying to influence a number of votes including the 2016 US presidential election and the European Union referendum.
However, the Czech Republic’s presidential election is thought to be one of the Kremlin’s most important targets, according to Czech-based pro-Europe think tank European Values.
The report predicts the Czech Republic to be the “most intense battleground for Russian meddling efforts, especially during the presidential election”.
It reads: “Kremlin-inspired Czech disinformation efforts are almost completely united behind president Zeman and will probably play the role of creator and offer a platform to massive disinformation and smear campaigns against Zeman’s challengers.”
Sean Hanley, a senior lecturer at UCL School of Slavonic and East European Studies, said Mr Zeman’s feelings about Russia are shared by many Czechs.
He claimed that since the financial crash and the refugee crisis in Europe, many have felt the Czech Republic’s membership of the EU has not lived up to its promises – and Russia could offer an alternative lifestyle
Mr Hanley said: “There’s a scepticism towards the EU and further integration.
“It’s rooted in the fact that the EU was presented as an end point for economic prosperity and catching up with the West, which hasn’t worked out for everyone.
“Czech attitudes to Russia are very pragmatic, there isn’t great admiration for Putin. Their political stances are rooted in pragmatism and where their national interests lie.”
A poll ahead of Friday’s vote suggest Mr Zeman has a 47.6 per cent chance of victory, according to kdovyhrajevolby.cz website which combines polls with bookmakers’ odds.
His most serious challenger Jiri Drahos, former head of the Czech Academy of Sciences, scored 44.9 per cent.