"Many New Zealanders want to be able to go shopping over the long Easter weekend - but at present many shops are banned from opening by Government regulation," chief executive Mark Johnston said.
"In 2015, when people can shop 24/7 over the internet, the regulations really don't make sense, and it's time they were reviewed."
The law gave some retailers an unfair advantage over others, Mr Johnston said, because "it's filled with exemptions that render it meaningless".
"A corner dairy can open, but not a supermarket. You can go shopping in Queenstown or Taupo, but not Wanaka or Rotorua. A shop can be filled with workers packing internet orders - but it can't open the front door to the public. None of these restrictions make sense in 2015."
Retail NZ would write to the Government asking for changes to the law, he said, with an aim of bringing in new legislation in time for Easter 2016.
"I'm not saying every shop must open, that everyone must shop, or that everyone must work - but if people want to, why should the Government get in the way?"
Meanwhile, at least two retailers have vowed to defy the Easter trading laws.
Oderings director Darryn Odering said all 10 of its stores - five in Christchurch and five in the North Island - would open over the weekend.
The garden centre chain has opened every Easter weekend since 1972, Mr Odering told Newstalk ZB, and this one would be no different.
Easter trading laws were outdated, Mr Odering told the station, and needed to be changed.
Rival garden centre company Kings Plant Barn has also declared it will open all weekend.
