Thirty-four percent of senior managers say taking too little time off was the biggest mistake they made with their last vacation, according to an OfficeTeam survey released today. Not being able to get their mind off work was next with 25 percent, followed by 22 percent who said checking in with the office too much was their biggest vacation mistake.

Only 7 percent said they didn’t check in with the office enough, while 5 percent said they didn’t prepare or organize their work well prior to leaving.

The survey also found two in five workers don’t use all their paid vacation days. The reasons include wanting to save time in case they need it (30 percent) and too much work – don’t want to fall behind (30 percent).

“Managers may be hesitant to take extended time off because they fear their absence will be a hardship on other staff,” said Robert Hosking, executive director of OfficeTeam. “But a longer break can be a good opportunity to delegate projects to an employee who shows promise to see how that person manages while you’re away.”

The survey was developed by OfficeTeam, a Robert Half company, and conducted by an independent research firm. It included telephone interviews with more than 300 senior managers in the United States at companies with 20 or more employees.