The assisted dying bill was rejected by 330 votes to 118, putting those opposed in a majority of 212.
If passed, the bill would have given some terminally ill people the right to get medical assistance to end their lives, similar to the arrangements that are already legal in some countries, such as Switzerland.
The bill was hotly debated, with some MPs calling the plans “totally unacceptable” and arguing they would “legitimise suicide”. Others, meanwhile, applauded the possibility of having a “dignified and peaceful death”.
Protesters on both sides of the moral issue gathered outside the House of Commons during the debate.
The bill brought forward suggested adults with less than half a year to live could be given a lethal dose of drugs, but only if they were capable of taking it themselves.
Similar plans have been rejected several times before, but today’s vote was the first one on the issue in 18 years. The last time euthanasia was voted down in the Commons was in 1997.