The number of jobless people in the United States rose by 663,000 last month.
Figures from the Department of Labor show the unemployment rate rose to 8.5% from February's figure of 8.1%, meaning it is still at its highest since 1983.
Since the recession began in December 2007, 5.1 million jobs have been lost, 3.3 million of them in the past five months.
Although showing a severe deterioration, the figures were in line with expectations.
"This is still an ugly number. Just because it wasn't uglier than the consensus, doesn't mean it wasn't ugly," said Robert Macintosh, chief economist at Eaton Vance Corp in Boston.
"It's telling you we're in a deep recession and it's still going to be a while to get out of it, especially on the employment side of things."
The total number of unemployed people rose to 13.2 million in March, the figures showed.
Meanwhile, the number of people forced to work part-time, but who would prefer to work full-time, rose 423,000 to nine million.
The part-time figures are reflected in a fall in the average working week to 33.2 hours, the lowest since records began in 1964.
The job losses were spread across sectors with the federal government among the few employers increasing employment, but even the US Postal Service cut jobs during the month, with 1,200 staff being laid off.