He is also the father of fellow directors Jake Kasdan and Jonathan Kasdan.
For Disney, Kasdan wrote the remaining screenplay for George Lucas' Star Wars sequel The Empire Strikes Back after the death of Leigh Brackett, who wrote the first draft. Lucas later commissioned Kasdan to write the screenplay for Return of the Jedi.
Owing to his tremendous success in helping George Lucas shape the Star Wars films, J.J. Abrams hired Kasdan to co-write the screenplay for Star Wars: The Force Awakens, and Kasdan also produced the film. Kasdan later wrote the screenplay for the 2018 film, Solo. Shortly after that film's release, Kasdan announced that he will no longer work on the Star Wars franchise.