The final piece of concrete is to be poured on to the roof of Oxford's £109m state-of-the-art cancer centre, designed using patients' advice.
The new Oxford Cancer Centre will join cancer services based at the Radcliffe Infirmary, John Radcliffe Hospitals, and the Churchill Hospital site.
The Sheriff of Oxford, Councillor Susanna Pressel, will attend the ceremony, marking its completion.
The new facility, due to open in 2008, will include 10 new operating theatres.
It is being managed through the government's Private Finance Initiative (PFI).
Services at the centre will include additional medical and surgical beds for cancer patients, a new radiology department, linear accelerators for radiotherapy plus 12 additional places for chemotherapy patients.
It will also house physiotherapy services, a high dependency unit and a private patients' unit.