Students at Burgess Hill Girls are celebrating their GCSE results today.
More than half of students at the school in Keymer Road achieved 9/8 or A* and 74 per cent of students achieved 9-7, the equivalent of A*/A, a ten per cent increase on last year.
Sixty-two per cent gained at least seven or more grades 9-7, the equivalent of A*/A.
Amid concerns over the marking and grading of the new, 'harder' exams, the school said it 'continues to perform at the highest level'.
Liz Laybourn, headteacher, said: “We believe in challenging each individual to be ambitious and achieve the highest grades of which they are capable.
"Teachers work hard, going above and beyond, to ensure that girls meet these high standards and reach their full potential.
"Yet again, this year’s results prove that the Burgess Hill Girls experience adds significant value to each and every girl.
"Not only have they achieved superb grades across a wide range of subjects, the girls have also taken full advantage of the amazing opportunities that the school provides on the sporting, creative and enterprise fronts.”
Across all STEM subjects (science, technology, engineering and maths) 79 per cent of all entries were graded 9-7, the equivalent of A*/A, a nine per cent on last year.
A spokesman for the school added: "The 100 per cent grades 9/8, the equivalent of A*, in computer science challenge the widely held perception that the subject is ‘too hard’ and is more popular with boys than girls.
"In an all-girls environment subjects are free from gender stereotyping. Computer science is an increasingly popular subject at Burgess Hill Girls.
"Burgess Hill Girls achieved highly across a wide range of subjects. Ninety-two per cent of entries in creative subjects were graded 9-7, the equivalent of A*/A, and in the new tougher English language GCSE assessed solely by examination 71 per cent gained grades 9-7.
"Burgess Hill Girls achieve on average one GCSE grade higher than their baseline indicator demonstrating the value the school adds to each individual pupil."