The survey of professionals from 115 employers suggests two-thirds of firms are struggling to fill high-skilled roles. IT and technology (20%) and creative roles (14%) are proving the most challenging to fill.
More than half (56%) of the respondents said they wanted to see the visa system reformed to remove barriers to hiring high-skilled individuals from overseas.
Additionally, more than one-third (37%) of business in the capital said they offer careers advice and talks to develop skills for the future.
Despite the shortage of skills, 59% of businesses are optimistic about the future of the economy and 47% are confident about their own company's business prospects over the next six months.
CBI London director Lucy Haynes called on businesses to work closely with schools and colleges to ensure future professionals are "equipped with the skills" to drive the capital forward.
She added that looking at policies to make London desirable to skilled workers from all walks of life is crucial.
"To keep the capital internationally competitive, as well as attractive to skilled workers, policymakers need to look at further streamlining the visa system," she said. "We would also like to see the mayor take urgent action to free up land for house building, and invest more in the city’s transport infrastructure.”
KPMG London chairman Richard Reid added that the challenges around finding skills in the capital are becoming "increasingly complex".
"Failure to act swiftly on the skills agenda will undoubtedly see London slip in its global reputation as a world-class business destination," he warned.