"Last year had the largest number of elephants poached in Africa on record," Wendy Elliott, WWF Global Species program manager, told Reuters in a telephone interview about the report.
There had been many large seizures of elephant ivory of more than 800 kg (1,760 lbs), she added, a sign that "there is a growing involvement of organized crime in this trade".
"Poor performances by key countries are threatening the survival of wild rhinos, tigers and elephants", the WWF said in a statement about the report's findings, which are due to be presented at a meeting of the Convention on International Trade in Endangered Species in Geneva (CITES) this week.
CITES bans virtually all trade in elephant ivory, rhino horns and tiger parts - often used in traditional medicines - in order to try to save them from extinction. The animals are also under threat from other factors such as loss of habitat, climate change and pollution.
Red to green
The report, which gave red, yellow or green marks to signal failure, partial failure or progress, gave worst marks to Vietnam, Laos and Mozambique with two red marks apiece.
Elliott said that demand for ground-up rhino horn in Vietnam had partly been spurred by an ill-founded rumor that it helped cure cancer. WWF urged Vietnam to do more to crack down, suggesting it tackled the Internet advertising of rhino parts.
Demand in Vietnam "has fuelled a poaching crisis in South Africa. A record 448 South African rhinos were killed for their horns in 2011 and the country ... has lost an additional 262 already this year", it added.
WWF said Mozambique had failed to halt the involvement of its citizens in rhino poaching in South Africa and had not controlled the ivory trade despite some improved checks at ports.
Laos and Vietnam had failed to report how they would comply with a ban on the captive breeding of tigers for medicine, it added. Laos was also failing to control the ivory trade.
China, traditionally a major market for animal parts, was awarded green marks for its efforts to slow the illegal trade in rhinos and tigers, but a yellow mark for its work on the trade in elephant ivory, prized when carved into costly ornaments. WWF said Beijing should do more to police its domestic ivory market.
India and Nepal were the only nations to get green ratings for all three animals.
Elliott said many nations already had sufficiently strict laws. "The problems now is really enforcement," she said. "The solution is not to ban the trade - it's already illegal."