The surprise finding, from a survey of 300 heads of IT in the public and private sectors, comes after three years of economic downturn during which IT chiefs have come under pressure to demonstrate a quick return on IT investment to the board.
Only 25% of the IT directors surveyed said their ability to measure and demonstrate the value of IT had a "significant impact" on their own success at work.
Most respondents admitted that they struggled to measure the benefits of IT investment, and 71% said their attempts to do so had only been "somewhat" or "not" unsuccessful.
Criteria used by IT directors to measure the value of IT included increased productivity (67%), and decreased costs (66%).
"I would have thought that demonstrating the value of IT would be the number one objective of a CIO," said Neville Howard, technology strategy partner at Deloitte & Touche. "It is staggering to think only one in four IT directors think so.
Despite the growing importance of IT to business, only 9% of those surveyed saw themselves as leading the development of business strategy and 47% said they were involved in setting business goals and budgets.
Philip Virgo, strategic adviser to the Institute for the Management of Information Systems, said the findings reflected polarised views on the role an IT director should take.
"There is a clear split between businesses," he said. "In one the IT director is a business planner and technology adviser and in the other they are the chief plumber in charge of a key utility, like electricity, which the business could not operate without".