Its decision, however, was suspended for one year to allow lawmakers an opportunity to enact new rules surrounding the divisive issue.
A legal challenge to the existing law was brought by the families of two women in westernmost British Columbia province who have since died, and was supported civil liberties groups.
One of the women, Gloria Taylor, died of an infection after suffering from a neurodegenerative disease.
The other, Kay Carter, travelled to Switzerland, where she was allowed to commit doctor-assisted suicide, saying before she died that she was terrified at age 89 of "dying inch by inch."
The court at the time expressed concern over protecting vulnerable persons, but in its new ruling pointed to changed social values.
