Robert De Niro was considered to play Dr. Otto Octavius.

He was offered the role after Tobey McGuire was injured; he was even screentested with a suit, according to a rumor.

Ed Harris was considered to play Dr. Otto Octavius.

Sam Neill was considered to play Dr. Otto Octavius.

Jim Norton played the role of "Surly Truck Driver" in Spider-Man, and Sam Rami wanted him to reprise his "he stinks and I don't like him" line in the sequel, this time talking about Doc Ock. Jim Norton was unavailable.