The Consumer Research found seven out of 10 people wanted their money to be invested ethically but only around 8600 people had signed up to invest in specially targeted ethical investment funds.
More than 2.7 million people are signed up to KiwiSaver with around $40 billion invested.
KiwiSaver investors can find out where their money is being invested by searching the Companies Office's Disclose register
But Consumer also warned the register may not give all the information people needed to know.
"Most schemes invest in global tracking funds, which means you need to dig deeper to find where these funds invest."
It urged members to question their KiwiSaver provider.
"Quiz your fund manager about its approach to responsible investment. Look for details on industries the fund screens, rather than general commitments to do the right thing. You can also ask what the fund is doing to support sustainability investing."
The research survey 1531 adults in March.