Some 10% of UK students who graduated last year were unable to find work, according official figures, up from 8% the year before.
The jobless rate among 2009 graduates is the highest in seven years, says the Higher Education Statistics Agency.
And the number of students who managed to find employment within six months has dropped from 62% to 59%.
The figures also reveal how the chances of students finding work depend on their choice of college subject.
The agency's figures are based on the experiences of 205,000 students six months after graduation.
This snapshot suggests that no medical students are out of work, but that 9% of language students are unemployed, rising to 14% of communications students, and 17% of those on computer science courses.
Universities Minister David Willetts said the overall figures showed that employers were continuing to recruit graduates in large numbers, "even though these are students who graduated at the height of the recession".
The National Union of Students (NUS) said it was "a particularly tough time for graduates looking to get themselves on the career ladder".
"University leavers will be the engines of economic recovery in the UK and the government must ensure that it invests in the creation of suitable jobs and secures access to employment opportunities to best utilise the vast pool of skills and knowledge emerging from our colleges and universities," said NUS president Aaron Porter.
The government wants colleges to give greater information about students' chances of finding work after graduation so they make better choices before they embark on a college courses.
"I have asked universities to provide employability statements to help people make the right choice about which course to take," Mr Willetts said.