Authorities at the scene provided scant details about the cause of the evacuation, which occurred between 8:30 and 8:45 a.m. Tuesday.
Employees gathered outside the mall as Truro fire fighters, police and Nova Scotia Power crews were called to the scene, along with EHS representatives.
At least one Zellers employee was seen going into an ambulance although there were no specific reports of injuries.
Truro fire chief Blois Currie told the Truro Daily News that smoke was seen in a vent unit.
And one shop owner at the mall was told that the problem was believed to have occurred in a heat exchange unit.
As of about noon, mall officials were still trying to determine the exact cause of the disruption.
More information to follow.