A Midland mental health trust will get the keys to a new 64-bed hospital five weeks ahead of schedule, enabling patients to move in by next May.
The new £50 million hospital replaces the existing Queen Elizabeth Psychiatric Hospital in Edgbaston, and will also include a ten bed intensive care unit for men.
A smaller facility will open at the same time in Showell Green Lane, Sparkhill.
Birmingham and Solihull Mental Health NHS Trust will take control of the new hospital in March 2008, which is set to open to patients two months later.
Kate Phipp, the trust's service director, said: "This is excellent news, people who need to come into hospital in south Birmingham will no longer have to share a cramped dormitory, they will have single en-suite rooms with modern therapeutic space.
"For our staff, too, the new buildings are much better places to work in and we can bring different teams and services together on the same site. From March we will fit out the buildings and provide extra training for our staff so that we are ready to open in May 2008."
The hospital will also house a specialist unit for women suffering mental health problems during pregnancy, along with services for people with eating disorders, an education and training centre and Birmingham University's psychiatry department.
Sue Turner, the trust's chief executive, said: "One in four people will suffer a mental health problem at some time in their life.
"Increasingly our emphasis is on providing services as close to patients' homes and communities as possible, which it has been shown is better for their mental health.
"The prevalence of mental health problems means that mentally ill people are us, our friends, our children and our parents.
"We now have the opportunity of creating fantastic new services that we can all be proud of."