Overview

• Eric Stoltz was cast as Marty McFly in November 1984 at Sidney Sheinberg’s recommendation and began filming that month.
• Stoltz’s intense, method-acting approach reportedly clashed with the film’s comedic tone and resulted in physical friction with co-stars.
• Director Robert Zemeckis dismissed Stoltz on January 10, 1985 and brought in Michael J. Fox, a move that added an estimated $3–4 million to the budget.
• Michael J. Fox juggled daytime shoots for Family Ties and night shoots on Back to the Future, often working 18–20 hour days after stepping into the role.
• At a 2025 Calgary Expo panel, Fox and Stoltz reflected on their switch-over, praising each other’s resilience and forging a lasting friendship.