The UK's technology industry must do more to keep women within its folds if it wants long-term success, according to a report by Intellect.
The research, by the hi-tech trade group and the Department of Trade and Industry (DTI), said there was an "old boys club" in parts of the industry.
Action was needed to ensure that all was being done to recruit, motivate and retain women in hi-tech work.
It concluded there should be more equality and support in the workplace.
The report said women left the industry because of long hours, few networking opportunities and a perceived male-domination of hi-tech industry culture.
The research also pointed to the lack of opportunities for part-time workers, particularly for women seeking more senior positions.
Part-time work was also identified as having a poor image within the industry. Those who work part-time said they were not given the same responsibilities or opportunities as full-time colleagues.
Many women questioned reported that they would be more inclined to stay if there was less pressure to work long hours in a full-time role.
Vital for UK
"It is vital for the UK's productivity and competitiveness that the IT industry harnesses all of its skilled labour force potential," said Meg Munn, DTI Deputy Minister for Women and Equality.
"To meet the continuing growth in the use of IT, we need to encourage more people to consider IT related careers - and ensure that professional women in this sector are able to contribute fully at all stages in their career."
Office of National Statistics (ONS) figures show that the number of women employed in technology industries fell from 27% in 1997 to 21% in 2005.
Microsoft chief, Bill Gates, also recently lamented the lack of women working in the fields of technology and computer engineering.
Only 17% of students starting computer science degrees are women and the majority are from overseas.
The British Computer Society (BCS) also reported that 28% of UK organisations do not employ women technologists.
Industry commentators say women are put off from thinking about hi-tech careers because there is a lack of successful role models.
This is one of the areas which the DTI said it would be looking to improve, through work with various organisations.
"The UK IT industry is world leading, but it won't stay that way for long if we continue to haemorrhage valuable skilled women professionals from the sector," said John Higgins, from Intellect.
"If we want our organisations to grow then we must open our ears to the report's findings and recommendations."
Get them young
The problem of keeping women in male-dominated industries is also one which hampers science and engineering.
One organisation working to get women back into science, engineering and technology careers is the UK Resource Centre for Women in SET (Science, engineering and technology).
The centre is a key part of the UK government's 10-year investment framework in science and innovation. It works with employers and SET experts to provide support, training, mentoring schemes, and information.
One of the centre's aims is to see 40% of women sitting on industry and academic boards in senior positions in three years' time, or less.
A charter for women in science, engineering and technology was also launched in June to help tackle gender inequalities in UK universities.
The six-point charter, launched by the Athena Project and the Scientific Women's Academic Network (Swan), aims to stem the loss of women scientists.