The percentage of candidates achieving higher grade GCSEs in Wales rose by 1.5 per cent on the previous year to 55.6 per cent.
The highest proportion of A* to C grades was awarded in the single sciences, with 85.5 per cent of physics candidates gaining grade C or above; 86.8 per cent in biology and 78.8 per cent in chemistry.
The overall pass rate for grades A* to G was 97.9 per cent, an 0.2 per cent increase on 1996.
In the main subject areas, 55.9 per cent of candidates achieved higher grades in English; 46.6 per cent in maths and 46.6 per cent in double award sciences.
The total number of student entries was 227,303, a 5.9 per cent decrease on the previous year, reflecting the drop in the number of 15-year-olds.