Officials revealed that the number of students awarded an A* to C grade has fallen for the first time since the exams were taken in 1988 - and national figures reveal that 69.4 per cent of all GCSE exams were given at least a C grade - down 0.4 percentage points on last summer.
There was also a fall in the number of students awarded top grades. This year, 7.3 per cent of entries were given an A*, down 0.5 percentage points on 2011, while 22.4 per cent were given at least an A grade, down 0.8 percentage points.
The figures also show a decrease in the proportion of GCSEs awarded in at least grade C in the core subjects of English, maths and science.
According to ITV News, some pupils were warned that that their GCSE English papers may have been downgraded with a particular problem among pupils expecting C grades, who may instead end up with a D.
Teachers admitted that they were shocked by the results. Commenting on the website of the Times Educational Supplement, one teacher wrote: "Our results have been decimated. We're 10 per cent lower than last year. It does seem that our expected Cs became Ds and, because we're a school where most of our students are clustered around that C/D borderline, we've been hit hard. Members of my department are in a state of shock as they say they've never worked harder and this is the result."
However, the Daily Mail reports that the Joint Council for Qualifications (JCQ), which publishes the national results, insists that the drop in A*-C English results is a result of more candidates sitting the exam earlier, during the winter.
The JCQ also said that there was a 'dramatic' increase in entries for GCSE science - up 36.5 per cent - and that the fall in results at A*-C is partly due to a 'more demanding standard' and a 'significant' increase in entries by 15-year-olds.
Yesterday the Institute for Fiscal Studies (IFL) declared that GCSEs are no longer useful and should be axed because schools are using the system to 'boost their league table position'.
The worry is that schools encourage pupils to take easier exams or choose examination boards that offer the easiest papers.
Earlier this summer, Education Secretary Michael Gove announced plans for radical reforms to England's qualifications system - including the introduction of a new exam modelled on the old O-Level and plans to reduce competition between exam boards to offer the easiest papers.
The IFL backed Mr Gove's plan to allow only one board to offer an exam in any given subject and said that the 'sheer pace' of the increase in good grades over the years could mean that exams are getting easier.
So what do you think?
Should GCSEs be axed to make way for new, tougher exams? Or does it undermine pupils' achievements to suggest that exams are getting easier?
More on Parentdish: Results are out, what now?