Royal Berkshire Hospital has expanded A&E by eight beds.
Despite opening a new eight-bed A&E unit the Royal Berkshire Hospital in Reading is set to miss national performance targets this year.
The department is still "not big enough to cope" said Mary Sherry, Acting Chief Executive of the Royal Berkshire Hospital Trust.
She added that in the long term, the hospital needs to "look at a bigger redevelopment of the department at the front door."
National performance targets currently require A&E departments to treat 95% of patients within four hours.