The Muslim cohort at Ernest Bevin college is the second largest and now the highest-achieving faith group in the school, with 78 per cent getting five Cs or better.
Students there buck the national trend of underachievement by Muslim youth highlighted at a Muslim Youth conference last week.
The sports college in Tooting was named third most improved school in the country last year after its overall five A* to C GCSE measure rose from 18 to 60 per cent in four years.
Rukhsana Shiekh, senior vice-principal, said: "We have made Muslims feel valued and raised pupil and parental aspirations by showing what each student was capable of achieving."
The school gives Muslim boys access to a prayer room at lunch time, halal food and trips to the local mosque every Friday. Boys and girls in the mixed sixth-form can wear traditional dress. There are regular lessons and assemblies on all religions and the staff and student council proportionately represent the community. A Muslim former pupil has just joined the governing body.
Delegates at the conference in central London blamed negative media attention, the inactivity of Muslim parents and an unrepresentative school staff for low standards.