The Princess Royal has officially opened the new extension to Salisbury District Hospital.
Princess Anne also saw equipment pioneered at the hospital which helps patients move more easily after damage to the brain or spinal cord.
The new development houses the regional burns service, plastic surgery, speech therapy, maxillo facial outpatients, medical photography and elderly care.
A hospital spokesman the building would have an "enormous impact" on treatment.
"This is not only important for Salisbury and people throughout Wiltshire, Dorset and Hampshire who come here for general care, but also patients from across the whole region who need specialist treatment from our staff in burns and plastic surgery."
The princess was also presented with a bouquet of flowers by one of the younger patients from the children's unit, Shelley Cutler, aged eight.