Three-quarters handed A*-C grade
More than three-quarters of GCSEs were awarded at least a C grade in Northern Ireland, it was revealed.
Strong performances in English, maths and sciences contributed to the upturn.
But the proportion earning A*s fell slightly to 8.7%, compared with 8.9% last year, according to the Joint Council for Qualifications.
Girls continue to outperform boys across the grades and this year the gap has widened - a tenth of top grades were awarded to females.
Students took science, technology, engineering and mathematics subjects in increasing numbers but the total of grades for humanities like English literature also rose.
The popularity of GCSEs has increased, with entries rising from 171,354 last year to 176,301.
Director of qualifications Anne Marie Duffy said: " It's very pleasing to see an increase in performance at A* - C across English and mathematics, subjects that provide access to a wide range of courses and routes to employment.
"The STEM subjects continue to attract increased entries and to show a strong performance in terms of grades awarded.
"For the first time since 2007 we've seen an upturn in the number of GCSE entries in Northern Ireland. This is broadly in line with a rise in this year's Year 12 school population and is evidence of the continued value placed on GCSE qualifications."
Almost 33,000 pupils in Northern Ireland were due to receive their GCSE results today.
Northern Ireland exams body the Council for the Curriculum, Examinations and Assessment (CCEA) is offering, for the first time in many years, additional marks for punctuation, spelling and use of grammar in English literature, history, geography and religion.
Key statistics from today's results included:
:: 76.5% earned grades A*-C this year compared to 75.6% last year.
:: Boys won 6.6% of A*s compared to 7% last year while 10.8% of girls achieved top marks.
:: The proportion of English and mathematics entries awarded A* to C grades this year has risen. English is up 0.6 percentage points to 68.8% and mathematics has risen from 62.9% last year to 64.6%.
:: The proportion of entries awarded A* - C in biology sits at 91.2% (90.0% in 2012), 93.4% in chemistry (93.6% in 2012) and 94.7% in physics (93.7% in 2012).
Rises in the number of entries in biology, chemistry, physics, design and technology, engineering, ICT, mathematics and additional mathematics could indicate students thinking more about their future job prospects.
Humanities subjects were also on the increase, with more grades awarded this year in English literature, history and geography.
In modern languages, Spanish and Irish have again seen rises in the total of entries, while the downward trend for French and German continues. French still attracts the highest number of modern language examinations in Northern Ireland, with 6,250 grades awarded this year.
In England the GCSE system is to be radically reformed in a fresh effort to drive up standards.
Pupils from Northern Ireland who choose an English exam board in 2014 will only be tested at the end of their studies in a system known as a linear GCSE.
Most Northern Ireland students, who use the local exams body the CCEA, will continue to choose either modular or linear.
Stormont education minister John O'Dowd said: "Today is an important day in the lives of the young people receiving their GCSE results. Many of them will decide to continue their studies at school, whether their current school or a new one; others will opt to move into further education; still others will wish to move into training or employment.
"Regardless of what decisions they make, I would like to offer my congratulations to all who received their results this morning on their achievements."
Chris Keates, general secretary of the largest teaching union in Northern Ireland NASUWT, said pupils' success was achieved despite increased turbulence and uncertainty in the examinations system as the Government attempted to justify education reforms.
"Schools and young people need and deserve a stable qualifications structure in which they, the public and employers, can have confidence and they will be looking anxiously to the outcome of the education minister's review of the qualifications system," she said.
"The minister was forced into this review by the unilateral decision of the Secretary of State (Michael Gove) to announce reform of GCSEs in England without any consultation or reference to his ministerial counterparts in Northern Ireland or England.
"It will be critical that he acts to minimise turmoil for schools and young people and demonstrates commitment to and confidence in GCSEs as a world-class qualification."