The bill was supported by 40 MPs. Thirty-eight parliamentarians voted against, 10 abstained.
If the president signs the cohabitation bill into law, it will come into effect in 2016.
The cohabitation law provides a possibility for unmarried people to register their partnership, which would grant them some legal guarantees. The bill does not exclude same-sex couples from making use of the provision.
“In Protection of Family and Tradition”, an Estonian NGO, organised a protest rally on Sunday where it claimed that approving the law would violate moral foundations of the society. Supporters of the law say that it protects the rights of minorities better and makes the society healthier and more tolerant.