The report comes from the Captive Animals' Protection Society.
It's claimed just 9% of animals held in Welsh zoos are endangered in the wild.
An animal charity says many zoos claim they exist to help with conservation efforts but this isn't the case.
The report by the Captive Animals' Protection Society entitled "The Conservation Myth: How Zoos are not Saving Endangered Species" was released today as part of the charity's annual Zoo Awareness Weekend.
CAPS said they carried out the research to "debunk the claims put out by the zoo industry that zoos exist to conserve endangered species".
Using Freedom of Information requests, the charity was able to access stocklists of zoos in Wales which detailed how many species each zoo holds, a document zoos must submit annually to the local authority under zoo licensing laws.
They found that zoos were holding very few endangered species captive and are concerned that the public are being misled about what is going on at zoos.
CAPS' Campaigns Director, Nicola O'Brien said,
"Thanks to zoo propaganda, many people believe zoos exist to house and breed animals who are threatened in the wild. Yet the reality is the vast majority of animals in zoos are not threatened in the wild, so why are they being held captive? To us the reason is obvious - zoos are not focused on conservation at all.
The species displayed are there to attract the most visitors so that zoos can make a healthy profit."
Out of the ten most common species held in Welsh zoos, only two are classed as threatened and many are domestic species like the house mouse and guinea pig.
Meerkats were the most popular species, held in around 60% of the zoos studied.
This comes as little surprise given the fame and popularity of this species in the TV show 'Meerkat Manor' and the 'Compare the Meerkat' adverts.
Nicola continued: "It is clear that zoos are filling their cages with animals that are popular with visitors - ones that are cute and cuddly and can be interacted with. There is much evidence to show that wild animals face a range of welfare problems as result of being held captive. To continue to breed animals into existence to live their lives in a cage, for no clear benefit, is clearly not only unjustified but cruel."
The charity visited a selection of Wales in zoos and say they found animals living in run-down enclosures.
Whilst the research just focused on Wales, the charity says there is a similar picture across the UK. A study carried out in 2007 showed that just 5% of species in zoos in England are categorised as endangered in the wild.
Nicola commented: "Whilst we do not believe keeping endangered species in zoos actually contributes to conservation, we really would expect zoos that claim to focus on this issue to not be holding so many animals captive who are not of conservation concern.
"It is time zoos were honest with the public and stopped using conservation claims as a veil for animal exploitation."