The unanimous decision by a three-judge panel involved child porn found in Colorado-bound traveler James Linn Higerd's checked luggage.
Reports said the porn was found by a Pensacola Airport-based Transportation Security Agency agent doing a routine check for weapons and explosives.
The agent reported her discovery to local police and Higerd was detained. The police subsequently obtained search warrants that turned up more child porn on his computer and other electronics in his luggage.
The decision is the first of its kind according to the report, although the U.S. Supreme Court has not yet ruled on the issue.
Charlie Leocha, director of the Consumer Travel Alliance, an advocacy group based in Springfield, VA., who has opposed whole-body scanners said the ruling is a setback for air passengers.
"It's a continuing assault on the Fourth Amendment rights of travelers," Leocha said.
Federal courts in Ohio and Hawaii have suppressed evidence in two similar searches, ruling they violated the Fourth Amendment's ban on unreasonable searches and seizures.
But the Florida court said the major difference between those two cases is that the TSA agent testified that she examined the luggage only for dangerous materials.
In the other cases, the TSA agents crossed the line by purposely looking for child porn and even cash. Higerd’s bag was reportedly already screened by machine and was inspected by hand.
"We hold that the TSA agent was not engaged in 'general law enforcement objectives' when she discovered the child pornography," district judge Bradford L. Thomas said.
Sandi Copes, a spokeswoman for Florida Attorney General Bill McCollum, said he respects the court's ruling.
Higerd pleaded no contest to 194 counts of possessing child pornography but reserved his right to appeal Circuit Judge Nickolas Geeker's denial of his motion to suppress the evidence.
Higerd was sentenced to two and a half years in prison.