Four out of 10 New Zealanders witnessed prejudice in the last 12 months and age came out as the most common reason for discrimination, according to a survey.
The research suggested one in four people had personally suffered discrimination in their current workplace.
Of 1,500 Trade Me users in the random survey, 22 percent said discrimination was caused by age, followed by 18 percent due to ethnicity and 18 percent due to gender.
Three-quarters of those surveyed said their age affected their chance of getting a job.
Forty percent of women had personally experienced discrimination when applying for a job, and half believed their gender had affected their chance of getting a job.
A third of respondents took no action when they saw or experienced prejudice, and that rose to half among under 25s.
Head of Trade Me Jobs Jeremy Wade said it was not good news.
"Sadly, of those respondents who had personally experienced discrimination, 92 percent said it happened more than once," he said.
"Of those who had personally been discriminated against, women were more likely to speak up, with 55 percent raising the incident verbally or in writing, compared to 49 percent of men."
"New Zealanders under the age of 25 are less likely to take action after they have experienced prejudice, with around half of respondents saying they chose to keep quiet.
"Young people starting out in the workplace are often not as sure of themselves as those who have been in the workforce longer. The findings highlight the duty of care we have in making sure we have a safe workplace for all employees, especially our more vulnerable."
Mr Wade said ageism was alive in New Zealand, with one-third of Kiwis stating they'd been subject to discrimination when applying for a job.
"Many sectors are experiencing talent shortages and it would be a real shame if this is being exacerbated by age bias.
"We also have an aging population and if we want to continue to grow productivity, some employers might need to open their minds to the diverse thinking and experience that more mature workers can bring to the table."
However, against some perceptions, women were slightly more likely (14 percent) than men (12 percent) to have asked for a pay rise.
"While we know from our own data that women are less likely to apply for high-paying roles, it seems women are more likely to ask for a pay rise than men," Mr Wade said.