More than 38,000 exam entries in England, Wales and Northern Ireland were regraded after schools asked for re-marks, the exams watchdog Ofqual says.
Overall, there was a 19% rise in requests for re-marks for this year's A-level, GCSE and AS-level exams.
Ofqual says the numbers were affected by a rise in GCSE exam units.
But A-levels were not changed in this time and requests for checks for these also rose, by 11%, to just over 57,000.
Of these, more than 8,000 were eventually given a new grade.
Ofqual says across all the exams, about one in five requests for re-marks led to a new grade being given and that this number was slightly down on last year.
Competition for university places this year was intense, with tuition fees set to rise for many students in the UK.
And there were about a dozen errors in this year's exam papers, taken by pupils in England, Wales and Northern Ireland.
More exam units
Ofqual says the regrading figures should be seen in context: that in 2011, there were more than 18 million entries for exam and assessment units.
The numbers have risen dramatically in recent years due to changes in GCSEs and the increase will be reflected in the number of requests for re-marks, the watchdog says.
The proportion of exam entries given a new grade as a result of a re-mark is less than a half of one percent of the total entries, it says.
GCSEs became increasingly modular in recent years - with many being taken in chunks throughout the year.
But that is going to be reversed, under changes being brought in by the Education Secretary Michael Gove.
He says most exams should be taken at the end of a two-year course to make them more rigorous. The changes will affect pupils beginning GCSE courses next September.