Liev Schreiber was given a muscle suit to wear for his role as Victor Creed, similar to what Vinnie Jones (Juggernaut) wore in X-Men: The Last Stand (2006), to make his physique look comparable to Hugh Jackman's two hundred twenty pound figure. The suit made Schreiber feel "humiliated", and he requested a chance to gain real muscle. He trained for three months while filming Defiance (2008) in Lithuania, and continued to train alongside Jackman during filming. Jackman also made Schreiber add a great deal of protein to his diet, which Schreiber called "the genocide of chickens." In the end, Schreiber gained forty pounds, and had to buy several new suits due to his back gaining several inches in width: "I can't fit into my favorite suit now. But I felt like I owed it to the genre to be big."
In this movie, Logan fights in the American Civil War, World War I, World War II, and the Vietnam War. In the comics, he participated in World War I and World War II, even teaming up with Captain America in the latter.
In the flashback to Africa, a young black girl with white hair can be seen. This is the young Ororo Monroe (Storm), the future X-Men member. This scene was removed from the final cut, but appears as a deleted scene in the DVD.
Hugh Jackman expressed disappointment over this movie, admitting it fell short of his expectations and did not do the character of Wolverine justice: "Somehow, the first Wolverine movie ended up looking like the fourth X-Men - just with different characters." Subsequently, he and the rest of the crew sought to do a better job with The Wolverine (2013).
Hugh Jackman recommended his Kate & Leopold (2001) co-star Liev Schreiber for the role of Sabretooth, describing him as having the necessary competitive streak to portray Sabretooth. During filming, they dared each other to perform more and more of their own stunts.