Alex Sink will not run for Congress again this year.
The Democrat said in a statement Tuesday that she will not wage another campaign in the fall after losing a high-stakes special House election last month to Republican David Jolly.
Sink lost by less than two percentage points in a swing-voting district in the St. Petersburg area, and Democrats had lobbied her to stage a rematch in November.
The race largely turned on President Barack Obama's health care law, with Jolly calling for the measure to be repealed and replaced.
Sink said in her statement that she would find new ways to serve Florida.
Republicans cast the news as a sign of Democrats' diminishing electoral prospects. Democrats said their eventual nominee would prevail on Election Day.