Ron Webster checked out a copy of Structure and Function in Primitive Society in 1953 when he was working as a research assistant at the school's social sciences department.
It wasn't until recently that he realized he still had the book in his possession and returned it to the library.
"Ron had been warned very firmly by the friends he plays cards with at the local pub that he would be landed with an enormous fine, and feel the full force of the law," said Webster's son-in-law, Rick Walker, who took him on the trip to deliver the book. "They didn't expect to see him again."
University librarian Phil Sykes said the library staff were "amazed" about the return.
"They called me and said 'you've got to come down. There's a gentleman trying to return a book he took out in 1953. He's 91-years-old!' " Sykes said. "When I came down they were sat with him having a cup of tea and a chat and I said: 'I believe I've got a disciplinary issue to deal with'. We had about an hour talking about it."
Sykes said he waived the fee of $7,634.48 "on the condition that Mr Webster agreed, henceforth, to live an exemplary life and return all his books on time."