However, smoking is not a ground in the Act.
"An employer can refuse to hire someone if they smoke because smoking is not covered by the Human Rights Act.
"Some employers have negative attitudes to smokers and may refuse to hire them."
The Human Rights Commission received complaints about this "from time to time", although it was not common, she said.
Some people argue that smoking is a disability, but in other countries where this argument has been legally tested, the courts have all held that smoking is not a disability.
Employsure senior employment relations expert Vanessa Bainbridge said no law dealt solely with job advertisements, and what could and could not be referenced in them.
"While the job advert might seem to be discriminating against smokers, it's likely that, under the law, it actually isn't," Bainbridge said.
Banning smoking in workplaces like bars and restaurants is permitted under the Smoke-free Environments Act.
This Act is intended to protect non-smokers from being affected by smoking.
"Most workplaces are alcohol-free so, it is common for employers to expect the same standard for a smoke-free workplace," Bainbridge said.
It has also become a workplace safety issue.
"Secondhand smoke has been recognised as a significant workplace hazard, shifting the focus from bar or café patrons' rights to employers' responsibility to provide a healthy, safe workplace for workers," she said.
