Nearly 80% of Catalans have opted to secede from Spain in the latest informal and non-binding referendum.
Initial results have begun to emerge following the polling in Spain's semi-autonomous region which drew about two million voters.
According to the provisional results, about 80.72% of Catalans who cast their ballots have backed independence for Spain's wealthy north-eastern region.
Pro-secession leaders have hailed the symbolic vote and hope the results would pave the way for the formal independence of the region from Spain despite strong opposition from the federal government.
"We have earned the right to a referendum. Once again, Catalonia has shown that it wants to rule itself," Catalan leader Arthur Mas told cheering supporters.
The voters were asked two questions with the first one being: "Do you want Catalonia to be a state?" In case of a "yes" for the first question, the second one was: "Do you want Catalonia to be an independent state?"
The voting took place after Spain's Constitutional Court stonewalled earlier efforts to hold a formal referendum even though it was non-binding.
The exercise has drawn stinging criticism from the central government which is fiercely against Catalonia's independence.
"The government considers this to be a day of political propaganda organised by pro-independence forces and devoid of any kind of democratic validity," Spain's Justice Minister Rafael Catala said in a statement, adding that the vote was " a sterile and useless act".
Tensions between Catalonia - which speaks its own language and has a population of 7.5 million people - and Spain have been increasing in the past several years with continuous calls for secession.
Madrid has been arguing on constitutional grounds that a region which has just about 16% of the country's population cannot be allowed to decide its own fate.
The referendum has come within months of the Scottish referendum in which voters chose to remain in the UK.