Bentley's attorney, Shannon Polk, said the lawsuit filed in Cuyahoga County Common Pleas Court seeks at least $25,000 in damages for alleged fraud and negligent misrepresentation. Bentley could seek more money in court.
Polk said Bentley nearly died from the infection while he was rehabbing from a knee injury.
"They told him their facility was the best," Polk said. "But they never told him about a host of unsanitary conditions there. And they never told him about the list of others who contracted staph before he chose to rehab there."
The Browns declined to comment on Thursday.
The lawsuit was first reported by AOL Fanhouse.
Bentley never played a game for the Browns after signing a six-year, $36 million contract as a free agent. He tore his left patella tendon in training camp in 2006, and his career never recovered after the infection.
In 2007, Bentley told The Associated Press that he had undergone four operations since getting hurt, the final two to clean out the staph infection, which ate away at his tendon. The virus became so severe that doctors considered amputating his leg.
"At one point, I was so sick they weren't sure I was going to live through the night," Bentley told the AP.
The lawsuit alleges the Browns' training facility in suburban Berea has been portrayed to players and player prospects "as a world-class facility at which 'state-of-the-art' physical training, medical care and treatment and other rehabilitative services are provided."
Bentley's repaired knee became swollen and he was diagnosed with staph infection within weeks of beginning rehabilitation at the facility in July 2006, according to the lawsuit. The lawsuit also says the Browns failed to sanitize equipment.
The Browns had at least six players stricken with some sort of staph infection in recent years, including former receiver Joe Jurevicius, who settled a similar lawsuit with the team in June. Terms of the settlement were not disclosed.
When the Jurevicius lawsuit was settled, team attorney Fred Nance said the Browns' sanitation and hygiene practices "have been and continue to be at the highest state-of-the-art level in the league."
The Browns' alarming rise in staph cases spurred the club to request assistance from the Cleveland Clinic, its health care provider and a sponsor. The Clinic twice sent a team to examine the team's headquarters and indoor practice fieldhouse in Berea.
The Clinic concluded the team was following proper procedure and CDC recommendations to prevent staph and that the five cases involving players were unrelated.
An NFL physicians survey of the 32 clubs determined there were 33 MRSA staph infections league-wide from 2006-08.
"Had the Browns disclosed that stuff to him, had they been straight with him, he would have never agreed to rehab at their training facility," Polk said.