For the second year running Sir John Cass Foundation and Redcoat Church of England secondary school in Stepney, east London, came joint top in the value added tables after 87 per cent of pupils gained five Cs or better at GCSE last year.
It puts its success down to the quality of the staff, specialist status and improved discipline.
Pupils can take GCSEs in 10 languages at the specialist language comprehensive, including Bengali, Urdu, Turkish and Russian.
The changes have made a big difference since 1995 - when just 8 per cent of the pupils were gaining five GCSEs.
The surge in standards is also reflected in applications: back in 1995 there were just 40 applications for the 180 places, compared to 840 last year.
The comprehensive doubled its GCSE pass rate in 1998, before it became a specialist language school.
Headteacher Hadyn Evans, said: "We closed the school buildings at lunchtimes and shortened the lunch break. We made changes to behaviour management and controlled dismissal. And we separated boys and girls for recreational activities."
Mr Evans said funding from Excellence in Cities has allowed them to build on their success by providing extra staff and computers. He also increased work-related subject options.