The Saving Private Ryan star has been in and out of the media for years due to his problems with substance abuse and addiction.
It unfortunately seems like Sizemore is in more hot water after it was revealed a stuntman from the US show Shooter is suing the actor for allegedly hitting him with a car while under the influence.
Stuntman Steve de Castro on Saturday filed the lawsuit, which seeks damages and medical expenses from Sizemore as well as the production company Paramount Pictures after he was hit with and then pinned under an SUV in July.
The lawsuit alleges Sizemore knew he was "intoxicated" before taking the wheel of the car and allegedly running de Castro over.
The incident occurred at a remote desert airport out of Los Angeles and his injuries were so severe he needed to be airlifted from the location.
Although the lawsuit fails to specifically list de Castro's injuries, it does say they were "numerous" and "internal and external".
He also claims that the "preventable accident" left him with lasting injuries that have borderline ruined his career as a stuntman.
According to the lawsuit, instead of terminating Sizemore's employment on the US drama, the producers took the actor's side.
De Castro's lawsuit hints at previous disagreements with the Black Hawk Down star as he claims the damage was "intentional" and that his injuries were "wilful and unprovoked physical acts of aggression."
Less than two weeks after the incident, Sizemore was arrested on suspicion of domestic violence against his ex-girlfriend.
He has pleaded not guilty to being abusive to her.
The actor has had a tumultuous past involving violence and addiction.
Steven Spielberg admitted he drug tested the star daily on the set of Saving Private Ryan to keep him sober and Sizemore has been arrested a number of times over the years, even spending a brief amount of time in jail.