This summer has seen a 0.2% increase in the proportion of entries awarded the top A* grade, rising to 8.9%.
The number of entries achieving A*- A have also seen an increase, rising by 0.2% to 28.2%.
More than three quarters of NI pupils performed at A* - C, an increase of 1.5%.
Performance data shows increased achievement in English, maths and science.
The percentage of entries achieving grades A* - C in English rose to 73.0%, in maths 66.2%, and in science rose to 64.8%.
The individual sciences saw an increase in high performance. The proportion of entries awarded A* - C in biology sits at 93.3%, 93.6% in chemistry and in physics 95.0%.
There were also notable performances in music and modern languages. The proportion of entries awarded A* - C in French was 85.5%, German 86.1%, Irish 95.5% and Spanish 91.4%. The corresponding figure for music was 91.5%.
More boys achieved top grades this year, but despite this improvement, girls maintained the gap in performance outperforming boys by 4.3% points at A*, by 10% points at A* - A and by 7.6% points at A* - C.
Despite the decrease in GCSE entries overall, there were notable increases in additional mathematics, business studies, German, ICT, mathematics, and statistics.
The popularity of STEM subjects such as biology, chemistry, design & technology and physics has been maintained. This is also the case for modern language subjects.
CCEA Director of Qualifications, Anne Marie Duffy, commented: "It is pleasing to see the hard work of Northern Ireland students and teachers being reflected in these results.
"The performance in core subjects of English and mathematics will provide strong foundations for learners as they move on to further education, training and employment.
"There were also notable performances in modern languages, science subjects and music."
She added: "This year there has been a 2.8% points fall in the Northern Ireland Year 12 school population, and we've seen GCSE entries decrease by 3,609.
"Against this backdrop, entries in business studies and ICT have risen while sciences and modern languages have maintained their popularity."
Today is a momentous occasion in the lives of thousands of local young people. It can be a time of high emotion but it should also be a time for young people to be proud of the hard work they have put in over the last two years towards their GCSEs.
Education Minister John O'Dowd
Congratulating those who got results, Minister O'Dowd said: "These young people now face choices about their future. Many will decide to continue their studies, either at their current school or perhaps in a new one.
"For some, the best choice will be to move into further education or into training or employment.
"Whatever choice they make and whatever grades received, I offer my sincere congratulations to all who have received results today.
"Inevitably there will be some who may feel disappointed that they did not achieve the grades they had hoped for."
The Minister continued: "To those I say, do not panic; this is only one chapter in your life, seek advice and move on to the next chapter. Talk to your teachers, to your parents and families and make use of the services available that can provide useful help and guidance.
"There is a future pathway for every young person and these services can help identify the right one for you."
Employment and Learning Minister, Dr Stephen Farry added: "The importance of making an informed decision following exam results is imperative to effective career planning.
"Taking time now to explore options will pay dividends in the future. There are many opportunities available to you and I would urge you to examine these fully.
"My Department's Careers Service provides professional, impartial careers help to people of all ages, tailored to individual needs. This includes assistance with CVs, job applications and interviews and advice on job trends, including industry sectors and occupations which will be important in the future."
"Northern Ireland's further education colleges also offer you the opportunity to study from a wide range of full-time courses to suit your career path, with options including A levels, GCSEs, NVQs and apprenticeships.
"You may want to consider an apprenticeship, where you have the opportunity to develop specialist skills, using new technology, giving you the chance to earn while you learn and gain qualifications that are recognised worldwide."