To pick the next president of their country, Ukrainians will soon head to the polls in a run-off election.
Voters face either choosing the incumbent president, Petro Poroshenko, and TV comedian, Volodymyr Zelensky, new to politics.
However, The TV celebrity, Mr Zelensky is favourite in the polls, having clearly dominated the first round of voting close to a month ago when 39 candidates were on the ticket.
Poll stations will open 08:00 local (05:00 GMT) and close exactly half a day later.
A lawsuit was called for Mr Zelensky to be barred from standing, however, a court in Kiev – the capital city of Ukraine – has rejected it.
Mr Volodymyr Zelensky distributed free tickets for the presidential debate which happened earlier this week, and a man had complained that it amounted to bribery.
On Friday the two candidates, Mr Poroshenko and Mr Zelensky appeared at Kiev’s Olympic stadium to debate for the first time.
And the victor of Sunday’s vote will be elected for a five-year term as president.
The position of presidency holds significant powers over the security, defence and foreign policy of the country.
Mr Zelensky is a popular entertainer but, it politically has not become clear during the election campaign what he really stands for.
He has however demonstrated that he can act presidential – but only by playing the part in a TV series.
Ukraine key facts
Population: 43.9m
GDP per capita: $8,800
GDP growth: 2.5%
Ethnic Ukrainians (est.):78%
Ethnic Russians (est.):17%
Unemployment (est.):9.2%
Source: CIA World Factbook