The NGO's Swiss branch sent people into 19 Swiss financial institutions, including giants UBS and Credit Suisse, who posed as potential investors to assess the quality of advice from banks on sustainable financial investments.
The investigation found bank advisers only asked prospective investors whether sustainability was important for them in half of the interviews.
When prospective investors asked for investments that are climate-friendly and compatible with the Paris Agreement they encountered some bank advisers unfamiliar with the 2015 pact on limiting global warming.
As for the so-called climate-friendly funds that were put forward, Greenpeace said they were barely more so than conventional investments after close analysis.
"None of the financial investment products put forward as climate-friendly could certify that only investments that comply with the climate objectives of the Paris Agreement are included in the portfolio," Greenpeace said in its report.
It called problematic that for almost 60 per cent of the funds analysed -- because they were recommended as climate-friendly -- the sustainability criteria was only applied to a part of the portfolio.
"These results are further proof that the Swiss financial centre is practising greenwashing with what it calls 'sustainable finance'," it said.
The investigation comes just months after Greenpeace screened more than 50 Swiss and Luxembourg funds and found that funds labelled as "sustainable", "fail to invest more capital in a sustainable economy than conventional funds."
