Edward Norton was approached to play Bruce Banner, but he turned it down. Norton didn't like the script despite being a Hulk fan. He later accepted the role in The Incredible Hulk (2008).
Nick Nolte grew his hair wildly for this movie when he was arrested for drunk driving and photographed for his now-infamous mug shot.
Nick Nolte (David Banner) used an oxygen tank throughout the production. Eric Bana recalled a moment where, after taking a hit of oxygen on set, Nolte turned to Bana and confided, "I don't really need this, it just makes them think you're fucking crazy and they pay attention."
Lou Ferrigno: (at around 12 mins) As a security guard. Ferrigno is best known for playing The Hulk in The Incredible Hulk (1977) and a few succeeding projects.
Stan Lee: (at around 12 mins) The creator of the Hulk (1962) appeared as a security guard. Lee ad-libbed his lines.