The Institute of Directors (IoD), which polled more than a thousand of its members between Friday and Sunday, added one in four planned to freeze recruitment following the surprise referendum result.
Almost two thirds or 64 per cent of IoD members think the result is negative for their business, while 23 per cent think it is positive. Nine percent say it makes no difference.
"Businesses will be busy working out how they are going to adapt and succeed after the referendum result," said Simon Walker, IoD director general.
"A majority of business leaders think the vote for Brexit is bad for them, and as a result plans for investment and hiring are being put on hold or scaled back."
More than a third of IoD members said the referendum vote will cause them to cut investment, against one in 10 who said they will increase investment.