The outcome has embarrassed Antonio Guterres's ruling Socialists. It proves the country's conservative Catholic church can have a powerful impact on government policy, reveals deep rifts between the Socialists themselves, and leaves the government in a constitutional tangle.
The negative result has also cast a shadow over a more controversial referendum, to be held in the autumn, on decentralising political power. The church has been campaigning for months for a "no" vote, and anti-abortion priests have threatened to excommunicate those voting in favour. It was church pressure that forced Mr Guterres to put the abortion law approved by parliament in February to the popular vote.
Mr Guterres's party pushed for a "yes" vote, but the Prime Minister himself, a devout Catholic, said it was a matter of individual conscience and that he personally would vote "no".
Since 1984, abortions have been permitted if the foetus is malformed or if the mother's health is in danger.Reuse content