The organisation found that SMEs could save £2,615 annually if they kept up-to-date with environmental regulations and good practice.
However, the website also found that half of SMEs do not believe good environmental practice can lead to reduced operating costs.
Martin Brocklehurst, head of external programmes at the environmental agency, acknowledged that SMEs struggle to keep on top of environmental regulations.
"In such a challenging financial climate it is more important than ever that they take advantage of the potential savings of going green," he said.
The evaluation, commissioned by Netregs, was carried out with 465 SMEs in March.
During 2007, poor awareness of environmental law among SMEs led to some firms being hit with fines of around £2.4m for pollution and environmental damage.
John Holbrow, chairman of the environmental and energy policy unit at the Federation of Small Businesses (FSB), said: "Environmental awareness should be a top priority for small businesses to help them save costs and improve their competitive edge."
Nearly a third of SMEs 'don't have any environmental policies'
Environmental guidance agency Netregs has said that 32% of SMEs fail to have any environmental policies or systems in place, and are "unlikely to develop them in the future".
