Bale visited the makeshift memorial of the victims near the cinema that was showing "The Dark Knight Rises" when the gunfire erupted, reported Daily Mail.
Carey Rottman, one of those injured in Friday's shooting, posted two photos of himself with Bale on his Facebook page.
Bale, dressed casually in a black T-shirt and jeans, thanked the staff, shook hands and agreed to have his photo taken with employees.
Janie Bowman-Hayes, assistant vice president of surgical services at sister hospital Swedish Medical Centre, said, "She and co-workers were attending a luncheon at The Medical Centre of Aurora when Bale came and thanked staff who tended to victims.
"He just said he wanted to come to thank all of us because he has been thinking about this. He knows the whole world has been thinking about this. He took it upon himself to come and thank us," she added.
Bale, who stars as Batman in "The Dark Knight Rises", previously issued a statement saying, "Words cannot express the horror that I feel. I cannot begin to truly understand the pain and grief of the victims and their loved ones, but my heart goes out to them."