The Conference Board, an industry group, said on Tuesday its index of consumer attitudes jumped to 54.9 in May from a revised 40.8 in April, the biggest one-month jump since April 2003. Economists had been looking for a much smaller rise to 42.0.
Fewer Americans said jobs were "hard to get," the survey found, with that measure slipping to 44.7% from 46.6%. Those saying jobs were plentiful climbed to a still meager 5.7%, but that was still higher than April's 4.9%.
"Consumers are considerably less pessimistic than they were earlier this year," said Lynn Franco, director of The Conference Board's Consumer Research Center.
The data was in line with other evidence suggesting that, while the economy continues to contract in the current quarter, the pace of deterioration has abated somewhat.
U.S. stocks extended their rally after the data, with the Dow Jones industrial average up 120 points or 1.5%.
The survey offered mixed messages regarding Americans' propensity to spend money. The proportion of those who said they planned on buying a car over the next six months rose to 5.5%, its highest in at least a year.
But fewer intended to buy homes -- only 2.3%, a tough break for one of the hardest hit sectors in the country's economic crisis. A separate report on Tuesday revealed U.S. home prices dropped 18.7% in March compared to a year earlier.