About 1200 DHL workers have planned a four-hour work stoppage at warehouses in NSW and Victoria on Monday.
The United Workers Union has been trying to negotiate new workplace agreements since March, including a 21 per cent pay rise over three years for NSW workers, and a 10 per cent rise each year for three years for Victorian workers.
DHL said it had taken measures to minimise the impact of the strike on customers.
"This is supported with the assistance of over 3000 DHL team members nationally who continue to service our customers," a spokesman said in a a statement.
The company said it had offered workers a wage increase in the form of an up-front, one-off payment.
DHL said it had taken measures to minimise the impact of the strike. (Bianca De Marchi/AAP PHOTOS)
"We regret that the UWU has been determined to lead the taking of protected industrial action against DHL, despite the fact that a large part of the workforce have accepted and received our offer," the spokesman said.
"However, we are confident that DHL employees will be able to vote up these agreements and receive wage increases as soon as possible."
The stoppage will affect big brands including Mattel, Nike, Australia Post and Samsung. The union said it had contacted DHL to ensure life-saving medicine deliveries would not be affected.
"This is a cost-of-living strike," UWU National Secretary Tim Kennedy said in a statement.
"Workers at DHL sites are earning below industry standards, working very hard to make ends meet."
The union has complained about a proposal to pay new employees less.
"How can they justify lower new starter rates when cost of living is going up?" DHL workers wrote in a statement.
"It can cause friction between people who do the same role for different pay rates, that isn't fair."