CHICAGO—The family of former National Football League player Dave Duerson filed suit against the National Football League on Thursday, alleging the league's concealment of information about concussion risks and failure to take adequate steps to address brain injuries led to brain damage that contributed to Mr. Duerson's suicide last year.

The suit, filed in Cook County Circuit Court in Chicago, also names football helmet manufacturer Riddell Inc.

The suit says Mr. Duerson suffered at least three concussions during his 11-year NFL career, and that examination of his brain at Boston University following his death indicated he suffered from progressive, advanced brain damage known as chronic traumatic encephalopathy.

The former Pro Bowl safety died in February 2011 after shooting himself in the chest.

“If the NFL would have taken the necessary steps to oversee and protect Dave Duerson by warning him of the dangers of head traumas, and educating and training all persons involved with the NFL teams in the recognition, prevention and treatment of concussive brain injuries, then Dave Duerson would not have suffered dangerous repetitive head trauma, would have recovered more rapidly and would not have sustained permanent damage to his brain which contributed to his death,” the suit said.

The Duerson family's suit is the latest in a growing number of concussion-related suits filed against the NFL and helmet makers by former players and their families.

“(Until) recent times, (the NFL) took the position publicly that there was no relationship between football-related concussions and brain damage,” said Thomas Demetrio, a partner with the Corboy & Demetrio P.C. law firm in Chicago, who is representing the Duerson family in the case. “So it’s more than not educating these players. It’s supplying false information.”

“I have a great deal of respect for the fact that prior to dying, (Duerson) told everyone close to him, pled with them, left notes for them…to get his brain to Boston University,” Mr. Demetrio said. “The family is carrying on what they knew their father wanted.”

Mr. Demetrio said the extent of damages would be determined during a requested trial.

Asked about the suit, an NFL spokesman said by email, “We have not seen the lawsuit and therefore our attorneys have not had an opportunity to review it. Dave Duerson was an outstanding football player and citizen who made so many positive contributions, but unfortunately encountered serious personal challenges later in his life. We sympathize with the Duerson family and continue to be saddened by this tragedy.”

“We have not yet received the complaint; however it is our policy to not comment on pending litigation,” Riddell said in an email statement.