The head of the Democratic National Committee, Debbie Wasserman Schultz, said in a video released Saturday that the party would be conducting a "top-to-bottom assessment of how we can do better" in midterm elections.
Democrats lost key races across the map on Tuesday.
Some are still undecided. But Republicans picked up a minimum of seven seats in the Senate, 10 in the House, and two governorships.
"Our party has a problem," said Wasserman Schultz. "We know we're right on the issues. The American people believe in the causes we're fighting for."
"But the electoral success we have when our presidential nominee is able to make a case to the country as a whole doesn't translate to other elections. That's why we lost in 2010. And it's why we lost on Tuesday. We've got to do better."
Wasserman Schultz said the DNC would form a committee of "key party stakeholders and experts" to conduct an "examination of what went wrong" and how Democrats can do a better job of "connecting in midterm elections."
The review would be a "top-to-bottom assessment of how we can do better in future midterm elections like these," she said.
Wasserman Schultz said the results of the study would be released by early next year, before the DNC's annual winter meeting.
After Republicans lost the presidential election in 2012, the head of their national committee, Reince Priebus, announced a similar overhaul effort.
The GOP "autopsy report," a 100-page document released last year, suggested Republicans embrace immigration reform and create "a tone that 'welcomes in'" minority communities.