A Kent comprehensive dubbed failing by inspectors is scoring well above the national average for pupils gaining five or more high-grade GCSEs.
During the past year Hayes secondary has also received two awards from the Specialist Schools Trust and one from the Learning and Skills Council for its results. But still the Bromley school languishes on Ofsted's list of underachievers.
Hayes was failed following a critical inspection in 2003. Weaknesses included teaching and assessment, particularly in Years 8 and 9, and a higher than average number of unqualified or less experienced teachers.
But despite an excellent report after a two-day HMI inspection in December, Hayes must remain on the list (along with 59 other schools) until its next inspection. Schools are usually re-inspected around two years after they are put on the underachieving list.
Last year, 79 per cent of pupils at Hayes school gained at least five grade Cs or better at GCSE, up from 69 per cent in 2003. This compares well with the national average of 59.2 per cent.
In key stage 3 tests, 95 per cent of pupils at Hayes achieved level 5 or above in English, 93 per cent in maths and 88 per cent in science compared to the national averages of 71 per cent achieving level 5 in English, 73 per cent in maths and 66 per cent in science.
Kieran Osborne, headteacher, said: "If good exam results and a good inspection do not get you off the list, what does? It is ridiculous.
"The HMI inspection raised the morale of teachers. It confirmed that we were doing well. We thought the underachieving school stigma would be removed but we have to wait for another full inspection. The teachers were disappointed. We felt we should not have been on the underachieving list in the first place. In the meantime we will look forward to the powers that be taking us off."
HM inspectors visit a sample of underachieving schools between six and 18 months after their Ofsted inspection. Since April 1 last year 60 schools have been designated as underachieving. HMIs will inspect 51.
Nine primary and two secondary schools were removed from the list during the spring term this year. A spokesman for Ofsted said: "Current legislation does not provide for HM inspectors to take schools off the underachieving list before a full inspection. Schools can apply for an early reinspection, if their request is supported by the local authority and they feel that they have made good or very good progress."