Lawmakers voted 138 to 84 with five abstentions to back the bill.
President Marcelo Rebelo de Sousa, who is known to have reservations, has yet to sign it the bill into law and can still veto the bill or refer it back to the Constitutional Court.
If approved, the bill will legalize doctor-assisted suicide for the terminally ill and severely injured.
The Portuguese Parliament voted to approve plans to introduce voluntary euthanasia laws on February 20, 2020.
In January, the Assembly of the Republic approved the final version of the law, with 136 votes supporting the bill. President Marcelo Rebelo de Sousa asked the country's Constitutional Court to evaluate the law on February 18.
On March 15, the top court said the law is imprecise in identifying the circumstances under which the procedures can occur and thus declared it unconstitutional. (ILKHA)