After analysing data on the board makeup of the digital firms that cluster around Old Street Procorre discovered that only 18 percent of 4,000 directors - around 720 people - were women.
The comparative percentage for FTSE-100 companies, often accused of having a 'glass ceiling', is 24 percent, it said.
"There is undoubtedly a shortage of female graduates with the right qualifications to go into the digital industries, but the gender gap in Silicon Roundabout cannot be explained by that alone," suggested Procorre contracts & HR manager, Wiktor Podgorski.
"Technology-based industries seem to be unable to attract the female talent available, and we have to look at the reasons why."
Only half of the women who graduate in science, technology, engineering and mathematics subjects were entering STEM-based careers compared to 68 percent of men, he said.
Procorre based its analysis of directorships using information held at Companies House, but is this job role the best measure for this kind of analysis
Silicon Roundabout is often viewed as a startup zone but a core of its companies go back further in time, some more than a decade. It's not clear how Procorre balanced young versus old companies in its data analysis but some of the gender issue it uncovered might reflect the past more than the present.
In addition, depending on the companies involved, directorships are often given to investors, in which case the board makeup reflects an imbalance in the finance and investment industry and not something rooted in technology or startups alone.
"Self-imposed targets seem to be working in the FTSE100 - they could also help the tech sector to raise its game," said Podgorski, who noted that self-imposed targets had raised board-level participating in the FTSE-100 sector.
"For Silicon Roundabout's concentration of high growth companies, there is also a need to reassure women that they are not hostile places to work."
Prominent UK female tech leaders include Kathryn Parsons, CEO of coding training centre Decoded, Joanna Shields, former head of Tech City UK (now working as Minister for Internet Safety and Security for the UK Government) and Sara Murray OBE, who founded and sold Confused.com to Admiral.
Probably the most famous British female tech entrepreneur, albeit from an earlier generation that pre-dates Silicon Roundabout, is Martha Lane-Fox, now a Baroness.
""I thought women would have much bigger role, because technology, or the internet, was a level playing field and its profound that did not happen," she said at a the everywomen in Tech forum in London earlier this year.
Despite suffering a backlash in recent times, Silicon Roundabout is still arguably the most dynamic tech zone in UK history, at least in terms of pure numbers - an estimated 15,000 startups in the year to mid-2013 according to one estimate.