A level results in Wales released today show an overall improvement, with 8.3% of results being achieved at grade A*.
For the first time in recent years, boys in Wales have outperformed girls at both grades A and A*.
Data shows there has been a rise in the number of students taking subjects such as Computer Science, Maths and Physics.
However, girls continued to outperform boys, with 98.2% of subject entries by girls this year gaining A*-E grades.
The percentage of students achieving A*-E grades is 97.7%, which is marginally better than previous years, which have ranged from 97.1% in 2010 to 97.6% in 2013.
Exam boards say they have seen a rise in entries for Business, Mathematics and Political Science at A level.
However, there has been a reduction in entries for a number of subjects such as Biology, English Literature, Geography and History.
There has also been a fall in the number of students taking up university places, early Ucas figures show.
In total, 416,310 people across the UK have taken up places, down 2% compared with the same point last year.
The fall comes in the wake of a drop in applications to start degree courses at UK universities this autumn, fuelled by factors including a fall in the 18 and 19-year-old population, changes to funding for nursing degrees and the possible impact of Brexit.
On a visit to John Frost School in Newport, Kirsty Williams said, "these set of results show an encouraging increase in the number achieving the top grades, with improvement in results across maths, biology,chemistry and physics.