A flagship academy costing £30m has been told it is underperforming by Ofsted inspectors.
The Marlowe Academy in Ramsgate was given a notice to improve after a visit by inspectors last month.
The education watchdog's report said students were underachieving in their GCSE English and mathematics examinations.
Principal Ian Johnson said the academy has made "amazing progress" since the Ofsted assessment in October.
Ofsted highlighted positive aspects of the academy and said it had worked hard with students, parents and carers to emphasise the importance of good attendance.
The report also noted that Mr Johnson's vision was "embraced wholeheartedly" by all staff.
Mr Johnson said: "Parents are very much with us".
The Marlowe Academy in Ramsgate was the first academy in Kent when it opened in 2005 after being redeveloped by the Roger De Haan Charitable Trust.
The academy replaced the Ramsgate School which closed after being put into special measures when it failed an Ofsted inspection in 2003.