The Standard & Poor's/Case-Shiller composite index of 20 metropolitan areas declined 0.5 per cent in November from October on a seasonally adjusted basis, though it was not as sharp as the 0.8 per cent fall expected by economists.
Prices have fallen 1.6 per cent in the past year.
Sixteen of the 20 cities showed annual price declines in November, while 19 of 20 cities showed monthly price drops.
The housing market has been struggling since home-buyer tax credits expired earlier this year. To take advantage of the tax credits, buyers had to sign purchase contracts by April 30.
"A double-dip could be confirmed before Spring," said David Blitzer, chairman of the index committee at S&P.
Blitzer defined a double-dip as both the ten and 20-city composite indices setting new post-peak lows.
He said the ten-city index is 4.8 per cent above its April 2009 low while the 20-city index is just 3.3 per cent higher than its low that same month.
Unadjusted for seasonal impact, the 20-city index fell 1.0 per cent in November after a 1.3 per cent decline in October.
"I find it hard to believe that if we get a double dip in home prices we could get the consumer back in a meaningful way. Right now it seems like a coin toss as to whether that's likely. So I'm disappointed," said Uri Landesman, president of Platinum Partners in New York.