For the first time, an ethical investment fund has topped the performance chart of 324 unit trusts investing in the UK stock market.
Ethical funds are attracting the interest of investors
The Co-operative Insurance Sustainable Leaders fund is the best performing unit trust over the past year.
Unit trusts pool investor cash to buy shares in various different companies.
An expert told the BBC that ethical funds were doing well because the sectors they avoided, such as tobacco and gambling, were underperforming.
In the past, ethical funds have had a reputation for poor performance, as the managers are restricted as to what firms and sectors they can invest in.
But in recent years, ethical funds have been growing in number and popularity.
Last year alone, 10 new ethical investment unit trusts were launched in the UK.
Mark Robertson, spokesman for the Ethical Investment Research Service, told BBC News the performance of ethical funds had also improved.
"Sectors such as tobacco, gambling and pharmaceuticals - seen as unethical - are not doing that well at present," he said.
"In addition, companies which are taking environmental issues more seriously seem to be doing better."