Mrs Fraser, who turns 99 in August, said it was an exciting time for QE Health, as it prepared to move to a new site that was part of a major redevelopment on the lakefront.
"It was built in a temporary fashion. It's time for something different. It's a good concept in a health spa place like Rotorua which has always offered relief for a long time.
"The concept of wellness goes back to my father's way of living."
Friends of QE Health chairwoman Judy O'Sullivan said Mrs Fraser was a natural choice for the patron role.
The group, which has been around for more than 65 years, has a wide role including working as ambassadors, helping support patients, visiting patients and helping fundraise for special amenities.