Michael J. Fox, 62, Christopher Lloyd, 84, and Lea Thompson, 62, attended the musical’s gala performance in New York City.
It comes nearly four decades after they starred as Marty McFly, Doc Brown and Lorraine Baines-McFly in the epic.
Posing outside the Winter Garden Theatre, the stars of the 1985 movie looked delighted to see one another.
They joined Casey Likes and Roger Bart, who portray Marty and Doc in the Broadway hit.
The film, which saw teenager Marty go back in time to 1955 and accidentally scupper his own parents’ romance, spawned two sequels, an animated series and multiple stage musicals.
Michael has spent his life raising awareness of Parkinson’s after his diagnosis at 29.
But the actor fears he won’t make it to his 80th birthday as his battle with the disease worsens.
In a recent interview with CBS Sunday Morning, Michael admitted: “I’ve been thinking about the mortality of it… I’m not gonna be 80.”
He added: “I’m not going to lie, it’s getting hard, it’s getting harder.
“Every day is tougher. But, but that’s — that’s the way it is.”
After his diagnosis, he set up the Michael J. Fox Foundation to improve the lives of others at risk of the disease.
The NHS states there are three main signs of the condition: Involuntary shaking of particular parts of the body, known as tremors, slow movement and stiff and inflexible muscles.
Guidance states that a person with the condition might also experience a wide range of other physical and psychological symptoms.