BLAENAU Gwent recorded the worst GCSE performance of all Wales' counties last year, despite being joint best for A-levels and top for boys' A-levels, figures show.
Only half of Blaenau Gwent's boys achieved five or more good GCSEs at grade C or above last year, according to figures published by Welsh Government this week.
The county also had the joint lowest figure in Wales of pupils who achieved five or more GCSEs at grade C or above, including English or Welsh first language in maths; the lowest figure for achieving five or more good GCSEs in any subject; and the lowest figure for five or more GCSE pass grades.
Across Gwent, three-quarters of last year's pupils achieved five or more good GCSEs at grade C or above in any subject.
The figures for all of Wales' local education authorities include independent schools.
Only half of Wales' cohort of 36,617 GCSE students in the academic year 2012/13 achieved five good GCSEs including English or Welsh first language and maths - producing a Welsh average of 53 per cent.
Four of Gwent's five counties fell below the Welsh average in this measure, with only Monmouthshire rising above.
Of Caerphilly 2,280 pupils who sat their GCSE exams last year, 46 per cent achieved this measure; of Blaenau Gwent's 729 pupils, that figure was 39 per cent, the joint lowest in Wales with Merthyr Tydfil.
For Torfaen's 1,405 pupils, 51 per cent got five or more good GCSEs including the three key subjects; for Monmouthshire's 918 pupils that figure was above the Welsh average at 57 per cent; and in Newport, 51 per cent of the county's 1,787 pupils achieved five or more GCSES at grade C or above, including English or Welsh first language and maths.
Looking at pupils who achieved five or more GCSEs at grade C or above, of any subject, Newport was the only Gwent county to exceed the Welsh average of 78 per cent - the other four fell short.
In Caerphilly the figure was 69 per cent, while in Blaenau Gwent, that figure dropped to 60 per cent, the lowest in Wales after Caerphilly.
Among Blaenau Gwent's boys this dropped again to 53 per cent, while 67 per cent of the county's girls achieved five or more good GCSEs in any subject.
Torfaen fell just short of the Welsh average at 77 per cent; in Monmouthshire the figure was 74 per cent; and Newport exceeded the Welsh average at 81 per cent.
Looking at pupils who achieved five or more GCSEs of any passing grade, Blaenau Gwent has the lowest percentage in Wales at 89 per cent, compared to a Welsh average of 93 per cent.
In comparison, the Isle of Anglesey, which had Wales' smallest GCSE cohort (two fewer than Blaenau Gwent) achieved 97 per cent.
Caerphilly, Monmouthshire and Newport dipped below the Welsh average to 92 per cent while Torfaen matched it at 93 per cent.
The picture was very different among Gwent's A-Level pupils.
Across Wales, the percentage of pupils aged 17 entering and passing the equivalent of two A-Levels was 96 per cent of the country's 11,706 pupils.
For Caerphilly's 525 pupils and 391 in Torfaen, they matched the Welsh average of 96 per cent, while Monmouthshire's 377 pupils and Newport's 731 A-Level pupils just missed the average, with 95 per cent of them passing the equivalent of two A-Levels.
However in Blaenau Gwent this figure jumped to 99 per cent of the county's 140 A-Level pupils passing, joint top in Wales with Powys and Ceredigion. Among the county's boys, the figure was 100 per cent - the highest for boys in Wales.