Economists surveyed by Briefing.com had forecast that confidence would improve to 56.1.
The survey was conducted after Congress passed an extension of the Bush-era tax cuts and a partial payroll tax holiday that will put more money into most taxpayers' paychecks in the new year.
But consumers are somewhat more concerned about the outlook for jobs following a jump in the unemployment rate in November to 9.8%. Those who believe jobs are hard to get rose 0.5 percentage point to 46.8%, and those who there will be fewer jobs six months from now crept up 0.4 point to 19.5%.
There have been a number of economic readings that had been getting better recently, and the holiday shopping season came in stronger than forecasts, with the National Retail Federation projecting that sales for the season rose 3.3% rather than its initial forecast of a 2.3% rise.
"Consumers' assessment of the current state of the economy and labor market remains tepid, and their outlook remains cautious," said Lynn Franco, director of the Conference Board's consumer research center. "Thus, all signs continue to suggest that the economic expansion will continue well into 2011, but that the pace of growth will remain moderate."
Consumer confidence posted strong gains from March through June of this year, and has been uneven since then, plunging to a 17-month low of 48.6 in September. December's decline marked the first drop since then, but even with drop the reading is now roughly unchanged from a year ago.
Consumer ConfidenceMeager increase forecast for holiday retail sales