Much of Sunday's voting was calm, but violence broke out in poorer areas as supporters of Mr Morales burnt ballot papers and ransacked polling stations.
One polling station was reported to have been destroyed, while elsewhere opponents of the referendum threw stones and clashed with those wanting to vote.
At least 20 people were injured, officials said, and unconfirmed reports said one man had died as police fired tear gas into a crowd.
The BBC's South America correspondent, Daniel Schweimler, said the result was always going to be in favour of greater autonomy since the opposition had said they would boycott the vote.
The question, our correspondent adds, is what happens next. Three other eastern provinces have said they too will vote on greater autonomy.
Land holdings
Mr Morales has promised radical reforms that he hopes will lead Bolivia, the poorest country in South America, out of poverty.
Leaders in Santa Cruz - home to about 25% of Bolivia's population - have demanded more local control over their resources.
They feel threatened by a draft constitution that proposes to limit large land holdings.
The proposals voted on in Sunday's poll include giving Santa Cruz more control over land distribution - and rich oil and gas reserves.
They also provide for the creation of a local police force.
Much of Sunday's voting was calm, but violence broke out in poorer areas as supporters of Mr Morales burnt ballot papers and ransacked polling stations.
One polling station was reported to have been destroyed, while elsewhere opponents of the referendum threw stones and clashed with those wanting to vote.
At least 20 people were injured, officials said, and unconfirmed reports said one man had died as police fired tear gas into a crowd.
The BBC's South America correspondent, Daniel Schweimler, said the result was always going to be in favour of greater autonomy since the opposition had said they would boycott the vote.
The question, our correspondent adds, is what happens next. Three other eastern provinces have said they too will vote on greater autonomy.
Much of Sunday's voting was calm, but violence broke out in poorer areas as supporters of Mr Morales burnt ballot papers and ransacked polling stations.
One polling station was reported to have been destroyed, while elsewhere opponents of the referendum threw stones and clashed with those wanting to vote.
At least 20 people were injured, officials said, and unconfirmed reports said one man had died as police fired tear gas into a crowd.
The BBC's South America correspondent, Daniel Schweimler, said the result was always going to be in favour of greater autonomy since the opposition had said they would boycott the vote.
The question, our correspondent adds, is what happens next. Three other eastern provinces have said they too will vote on greater autonomy.
