Aidan Quinn

When Aidan Quinn read the screenplay for This Is My Father, he says he was "just knocked out by the story." Good thing: The script, written by his brother Paul, was based on a tale of doomed romance their mother heard growing up in Ireland. "I called Paul through my tears," says Quinn, 40, "and said, 'I'll do anything to get this movie made.' "

The rest of the Quinn clan felt the same. Aidan and his sister Marion, 34, star in Father, which opens May 7; Paul, 39, made his directorial debut with it, and brother Declan, 41, was the cinematographer. (Their brother Robert, 37, a landscaper, had no role in the film.) Parents Teresa and Michael, he adds, were thrilled with the result.

Defying Hollywood convention, Quinn and his wife, actress Elizabeth Bracco, live in New Jersey with two young daughters. "Living here doesn't help my career," he says, "but it helps my sanity." Quinn says he would love to team up with his siblings again—after a break. "In about 25 years," he jokes, "I'll be ready for it."