Madrid: Catalans went to the polls on Sunday in a crucial regional election, billed as a de facto referendum on independence.
Polling stations in Spain's north-eastern province opened at 7.00 a.m. (local time) and will close at 6.00 p.m., BBC reported.
More than five million people are eligible to cast their votes.
The ruling Convergencia Party of Catalan leader Artur Mas and Esquerra Republicana have created a single list of candidates - under the banner "Together for Yes".
They said that Sunday's vote is a de facto referendum on independence from Spain.
They argued that the Spanish government has consistently refused to allow a legally recognised referendum, ignoring an unofficial vote backing independence in November 2014.
The anti-independence vote in Catalonia is split between a number of groups, including Spanish Prime Minister Mariano Rajoy's Popular Party.
The centre-right government in Madrid has described any breakaway plans as "nonsense".
Rajoy argues that because the loss of Catalonia would affect all of Spain, the democratic approach would be for all of the country to vote in a referendum on Catalonia's future.
At the same time, if "Together for Yes" fails to gain a majority, it would be tantamount to a serious defeat for the pro-independence movement.