Devon Primary Care Trust (PCT) has sold its historic Exeter offices for £9m.
The building may be turned into new homes and a hotel
The sale follows the merger this month of six trusts across the county to form one central PCT.
Dean Clarke House, which has been used for health care for the past 265 years, will be officially transferred to new owners Devon Lifestyles in November.
Proceeds of the sale are to be invested back into local NHS services. About 130 staff at the Exeter offices will be relocated to other sites in June 2007.
A trust spokeswoman said the Grade II listed building, which has been a hospital and an NHS site, was no longer "user-friendly" as administrative offices.
Devon Lifestyles has applied to turn the building into new homes, a hotel and office premises.
The new PCT has yet to decide where it will base its headquarters.