However, the head of the top-of-the-table South Hampstead High School for Girls said yesterday that she was more concerned to hold her pupils back than with pushing them to achieve more.
They were so highly motivated and ambitious that they risked suffering stress, said Jean Scott.
There were seven schools where every single exam entry gained at least a C-grade, all of them girls' schools.
Several girls' schools moved up towards the top of the list, with St Paul's girls rising from 12th place to second, and King Edward VI High School for Girls rising from 24th to fifth.
Meanwhile, some of the most famous boys' public schools dropped down the list, with Winchester, 11th last year, falling to 18th place and Eton, 13th last year, falling to 35th place.
Girls' GCSE scores have been improving faster than those of boys for several years, with girls doing better than their male classmates in most major subjects.
In 1995, the only subjects in which boys did better than girls were maths and biology. And the gap between the sexes appears to be getting wider, with 4.7 per cent more girls gaining A- C grades in 1988, and 8.2 per cent more doing so in 1995.
But South Hampstead's Jean Scott said her main concern was trying to reduce the pressures on her pupils rather than increasing them in order to push up exam scores.
Despite an ongoing debate over whether GCSEs are really necessary for pupils who are certain to do well at A-Level, the girls could see that the top university places went to those who had gained straight As in the exam, she said.
"We play it down as hard as we possibly can. We say GCSEs are nothing, it's A-Level, then your first degree, then your second degree that counts. But you can say that as much as you like - they know it's important.
"I think it's because more and more people are going to university. It's not just important to get in, it's important to get into the right place because there is definitely a hierarchy," she said.
Yesterday the Independent Schools Information Service, ISIS, which puts out the information on its 600 member secondary schools, said GCSE results were improving.
This year 43.3 per cent of entries were graded A of A*, compared with 41.8 per cent last year. "By every measure, independent schools have outstripped national performances," said national director David Woodhead.
How independent schools
performed at GCSE
Schools are listed by the percentage of entries gaining A* to C grades. Where two schools achieved the same percentage, the school which entered more candidates is listed highest. Statistics are provided by the Independent Schools Information Service.
No. of candidates %A*-C
South Hampstead High School, London 94 100.0
St Paul's Girls' School, London 88 100.0
Old Palace School of John Whitgift, Croydon 85 100.0
Wycombe Abbey School, High Wycombe 81 100.0
King Edward VI Girls' High, Birmingham 77 100.0
Withington Girls School, Manchester 74 100.0
St Mary's School, Calne 46 100.0
Bromley High School 82 99.9
Putney High School, London 81 99.9
St Helen's School, Northwood 81 99.9
Oxford High School 79 99.9
Haberdashers' Aske's, Borehamwood 163 99.8
North London Collegiate School, Edgware 103 99.8
St Catherine's School, Guildford 74 99.8
Guildford High School for Girls 72 99.8
Loughborough High School 71 99.8
Manchester Grammar School 207 99.7
Winchester College 139 99.7
The Cheltenham Ladies' College 132 99.7
Nottingham High School for Girls 117 99.7
Haberdashers' Aske's Girls, Elstree 115 99.6
Hymers College, Hull 107 99.6
St Martin's, Solihull 51 99.6
Sevenoaks School 138 99.5
King Edward's School, Birmingham 130 99.5
Bradford Girls' Grammar School 88 99.5
Channing School, London 48 99.5
Croydon High School, South Croydonn 110 99.4
The Godolphin & Latymer School, London 96 99.4
Westbourne School, Penarth 18 99.4
Bolton School (Girls Div.) 115 99.3
Central Newcastle High School 104 99.3
Leeds Girls' High School 83 99.3
Howell's School Llandaff, Cardiff 82 99.3
Eton College, Windsor 255 99.2
St Paul's School, London 153 99.2
King's School, Canterbury 148 99.2
Merchant Taylors' School, Northwood 133 99.2
Westminster School, London 32 99.2
Birkenhead High School GPDST 85 99.2
King's College School, London 151 99.1
Bury Grammar School (Girls) 120 99.1
King's High School for Girls, Warwick 79 99.1
St Swithun's School, Winchester 74 99.1
Talbot Heath School, Bournemouth 74 99.1
Stockport Grammar School 143 99.0
Rugby School 133 99.0
Wimbledon High School GPDST, London 79 99.0
St Albans High School for Girls 78 99.0
Tormead School, Guildford 67 99.0