Speaking to The Mirror, the 74-year-old said that his cancer has gone into remission, following a year of intensive radiotherapy treatment in London.
"I've won the fight and I'm feeling better than ever. Everyone was shocked by how well it all went," he said.
Prowse explained that he was diagnosed early after a worker for the Prostate Cancer Support Association urged him to get a blood test.
The former bodybuilder is best known for his portrayal of the masked Darth Vader in George Lucas's original Star Wars trilogy, though the character's voice was provided by James Earl Jones.