The bassist has teamed up with the American Idiot hitmakers' manager Pat Magnarella to co-produce upcoming drama Crickets, penned by his longtime pal and bar owner Alfredo Botello.
Crickets follows the relationship between two estranged brothers after one is diagnosed with a terminal illness.
Dirnt, who revealed in May (14) that his wife Brittney had been diagnosed with breast cancer, admits he was drawn to the project by the moving storyline, telling The Hollywood Reporter, "I've been - and a lot of people have been - affected by illnesses and it's a very relatable thing."
He adds, "I'm just kind of tired of junk food movies. Here's something that's a feel good, feel bad and feel everything movie."
In addition to producing, Dirnt will also help with the movie's soundtrack.
Green Day have previously contributed to film soundtracks for The Simpsons Movie, Transformers: Revenge of the Fallen and The Twilight Saga: Breaking Dawn - Part 2, while Armstrong has also tried his hand at acting, with roles in Tv series Haunted, medical drama Nurse Jackie and forthcoming musical drama Like Sunday, Like Rain.