Rod Duke, group managing director of Briscoes Group, which owns the Rebel Sport chain, said the increase in sales was immediate, and mainly from parents of young players.
"There's been a significant interest, which is half-expected," he said.
"People are now very well aware of the dangers and are aware of what they need to be doing, which is renewing helmets or buying new helmets."
Rebel Sport sells 14 different helmets, across two brands, ranging in price from $37.49 up to $119.99.
Hughes died at St Vincent's Hospital in Sydney last Thursday, two days after he was struck on the head by a cricket ball playing in a Sheffield Shield match at the SCG.
New Zealand Cricket recommends that all players facing hard balls wear head protection.
Many districts and associations already make helmets compulsory for underage players.
Jarrod Wrigley, manager of Cricket Express in Mt Eden, said most players were already well prepared before last week's high-profile death.
"Just about every kid - we reckon about 85 per cent of them - who walks into our shop to buy kit for playing hard ball buys a helmet. It's encouraged by the clubs and coaches," he said.
Mr Wrigley has not witnessed a spike in helmet sales and urged parents to be realistic about the danger.
"Yes, it's good to be safe and to be cautious, but your kid won't be facing a 135km/h cricket ball doing crazy things off a grass wicket."
Hadlee to attend Hughes' funeral
Sir Richard Hadlee will be representing New Zealand Cricket at the funeral of Phillip Hughes tomorrow.
The cricketing great, regarded as one of the top fast bowlers in history, was confirmed last night to be attending the funeral in Hughes' NSW east coast hometown of Macksville.
Hughes died on Thursday after being struck by a bouncer during a first-class match at the Sydney Cricket Ground two days earlier.
The young batsman's death has prompted an outpouring of grief from around the world. Thousands are expected at his funeral, with big screens planned to cater for overflow.
Australian Prime Minister Tony Abbott paid tribute to Hughes - who would have been 26 on Sunday - in Parliament yesterday.
"His death has so affected people because it happened in the midst of life at its most exuberant - he was 63 not out, on his way to a century and a return to the test team.
"Above all we honour a young man who has left us too soon, but who filled every moment of his 26 years with 60 seconds worth of distance run," Mr Abbott said.
X-Men actor Hugh Jackman posted a photo on instagram of a lone bat propped up on the Broadway stage where that day's performance of The River was to take place. "Just before curtain on Broadway ... Paying tribute to Phillip Hughes," he wrote.
- Teuila Fuatai and AAP
