Starting out as a child actor, he gained recognition for his performance in the 1993 film The Man Without a Face, in which he was directed by and starred alongside Mel Gibson.

[3][4] Stahl's first professional castings were small roles in Stranger at My Door (1991) and Woman With a Past (1992), although he had been acting in children's plays since he was four years old.

The 1993 film The Man Without a Face, directed by and co-starring Mel Gibson, helped boost Stahl's career at the age of 13.

He scored critical and box office success again with his role in the 2001 movie In the Bedroom, which starred Sissy Spacek and Tom Wilkinson as his parents.

Stahl has played two villains to good reviews: Bobby Kent in the film Bully (2001) and Roark Jr./Yellow Bastard in Sin City (2005).

[9] In April 2023, he appeared in a recurring role as Lucas on the Hulu television series Tiny Beautiful Things, opposite Kathryn Hahn.

In May 2024, Stahl starred in the suspense horror film What You Wish For, written and directed by Nicholas Tomnay and distributed by Magnolia Pictures.

[14] On December 27, 2012, Stahl was arrested at an adult film store in Hollywood, California, on suspicion of committing a lewd act.

[16] In a 2017 interview at the Dallas Comic Show, Stahl stated he had moved to Texas and was taking a leave of absence from acting to concentrate on family and sobriety.