About 193,500 Nevadans were out of work and seeking employment, said Bill Anderson, chief economist for the Nevada Department of Employment, Training and Rehabilitation.
Of those, 46 percent were considered long-term unemployed — people who have been without a job for 27 weeks or longer.
"Unfortunately, improvement on the jobs front failed to translate into fewer people out of work," Anderson said.
The December report shows the Great Recession continues to strangle the Silver State's economic recovery.
The seasonally adjusted jobless rate fell slightly in October after two months of record highs, before ticking up again in November to 14.3 percent.
Anderson said the report for December did contain some positive signs.
"December's increase does not change indications that the distressed labor market is starting to stabilize," he said. "It will be a long process to reverse the damage caused by the recession over the past few years."
Gov. Brian Sandoval, who will outline his budget proposal Monday in his State of the State address, has said job creation is a priority, and he will oppose any new taxes or fees to balance the budget.
Nevada's economy, highly dependent on sales and casino taxes, has been ravaged by the recession that began in 2007. The state's once robust construction industry that carried the economy through previous downturns collapsed with the nationwide housing crisis, exacerbating the economic freefall.
In 2006, nearly 150,000 people were employed in Nevada construction trades, representing 12 percent of employment statewide. Since then, 93,000 jobs have been lost, and the industry accounts for just 5 percent of the job market.
The national unemployment rate is 9.4 percent, and Nevada leads other states in joblessness, bankruptcies and foreclosures.
The jobless rate in Las Vegas climbed 0.6 percent in December to 14.9 percent, also a new high.
Elsewhere, the rate rose 0.5 percent to 13.8 percent in Reno-Sparks, 0.9 percent to 14 percent in Carson City, and 0.4 percent to 8 percent in Elko.