A third of IT staff are working 48 hours or more per week, according to a survey by the IT Job Board.
Of 318 IT staff questioned, 35% worked long hours, an increase of 2% on the August 2008 figure.
Some are working even harder with 7.3% saying they work 60 to 75 hours per week - this is an increase of one third on the 2008 figure.
Most say their longer hours are due to high volumes of work to be done, although some said it was expected by management. Staff are putting in the hours despite 75% of companies not paying overtime, and most say they haven't complained about the long working days.
Teresa Sperti, head of international marketing at The IT Job Board, said, "IT professionals have always worked long hours, trying to devise solutions to problems, or working to develop the next major piece of technology. But, what is clear to see, is that many are working longer hours as a result of the increased workload, and because it seems to be part of their company's overall working culture.
"Employers should be mindful to the impact that longer working hours could be having on their business, by way of decreased productivity, or employee poor health. And, they should step in to address any issues before they escalate."