How long did Sylvester Stallone take to write Rocky's screenplay?

Sylvester Stallone took three and a half days to write Rocky’s screenplay.

He began writing soon after watching Muhammad Ali fight Chuck Wepner at Richfield Coliseum in Ohio on March 24, 1975. Wepner lasted until the 15th round before being stopped, and the bout helped inspire Stallone to develop a story about an overlooked fighter receiving an unexpected championship opportunity. Stallone later disputed the idea that Wepner directly provided the screenplay’s inspiration, although the timing of the writing is well documented.

The script became the foundation for a remarkable production struggle. Stallone was not yet a major star, and United Artists preferred established actors such as Robert Redford, Ryan O’Neal, Burt Reynolds, or James Caan for the lead. Stallone refused to sell the screenplay unless he could play Rocky Balboa, even turning down a substantial offer for the script.

The finished film was made on a modest budget and became a major success. It earned the Academy Award for Best Picture and established Stallone as both a leading actor and a screenwriter. The three-and-a-half-day figure describes the initial screenplay-writing burst, not the entire development and revision process.