Justice Malcolm Rowe said in the ruling that a lower court judge erred in granting the injunction to Nalcor Energy to prevent native protesters from holding demonstrations near the site in Labrador.
Rowe said in his 38-page decision that the injunction was too broad and infringed on natives' right to carry out "normal aboriginal activities on the land."
The decision relates to a 12-hour gathering of members of the NunatuKavut Community Council in October 2012 on a stretch of a road controlled by Nalcor.
Nalcor sought the injunction the next day, which prohibited council members and their supporters from going within 50 metres of the road.
The demonstration also resulted in the arrests of several protesters and elders, but Todd Russell of the council says he expects the charges to be dropped against those arrested.