A survey by the Otago Daily Times found just two shops with notices on doors explaining they were closed because it was Good Friday.
The Shop Trading Hours Repeal Act 1990 requires most shops to remain closed on Good Friday and Easter Sunday.
Shops that sell necessities, such as dairies and service stations, are allowed to open.
Wanaka Photo and Digital owner Steve Worley said it was his 15th year of ignoring the Act.
He had been prosecuted twice - ordered to pay a $130 fine on the first occasion and convicted but not fined on the second occasion by a ''sympathetic'' judge who considered the law unfair.
Wanaka retailers have argued they should be exempt from the law requiring them to close, in the same way as the tourist towns of Queenstown and Taupo.
Mr Worley said the law was ''totally ridiculous and outdated'' and not ''in sync with current New Zealand life''.
It was his understanding the Ministry for Business, Innovation and Employment now acted only on complaints, and it was unlikely they would have sent an inspector to Wanaka.
The ministry declined an ODT request to discuss likely enforcement measures.
Businesses exempt from the law include pharmacies, duty-free stores and real estate agencies. Cafes, bars and restaurants are allowed to open as long as they sell only prepared or cooked food that is ready to be eaten immediately.
Elsewhere in New Zealand, garden centres were among those who flouted the law.
Oderings garden centre has opened its 10 stores over the weekend.
The garden centre chain has opened every Easter weekend since 1972.
''It's a tradition,'' Hamilton Oderings manager Ellen Hines said.
''It's been a busy day, I can't believe it - people beat me to work.''
While a labour inspector had not turned up by the afternoon, Ms Hines said she was expecting a visit.
Rival garden centre company Kings Plant Barn also opened its doors yesterday.
The Ministry of Business, Innovation and Employment did not say how many businesses it visited yesterday.
Its website said there were three and a-half days when almost all shops were required to be closed - Christmas Day, Good Friday, Easter Sunday and Anzac Day, until 1pm.
