Lead author Associate Professor Tony Reeder said the findings showed average levels of sun protection were poor across all nine groups, with forestry, horticulture, construction and farming scoring the lowest.
Viticulture scored the highest.
There was no significant link between participants' sun-protection knowledge and their use of protective practices.
"However, we found good evidence that employees were more likely to protect themselves if their workplaces provided sun-protective equipment and supported and promoted its use.''
Workplace action may be the key to reducing harmful sun exposure and associated skin cancer risk, said the researchers.
"Our research suggests that workplaces need to lead the way by providing appropriate protective gear and promoting a collective culture in which sun protection is seen as a priority,'' said Professor Reeder.
Outdoor workers make up nearly 15 per cent of the New Zealand workforce.
Skin cancer accounts for about 80 percent of new cancers registered each year, or 70,000 cases. About 2000 are melanoma, which represents one of the highest rates in the world, and more than 400 New Zealanders die of skin cancer each year.
The study has been published in the latest issue of the international Journal of Occupational Health.