ST Louis Grammar School, Ballymena, has become the first school in Northern Ireland to have achieved a 100% pass rate in the number of A*-C A-Level grades.
The results were published in last week's The Irish News grammar school league tables, which the school has topped for the past three years.
Two other Ballymena schools also made the cut in the league table, which details schools with the highest percentage of pupils achieving three or more A-Levels at grades A*-C.
Cambridge House Grammar School was placed at number 13 with a 87.2% pass rate while Ballymena Academy was placed at number 30 with a 81.3% pass rate.
St Louis Grammar School has cemented its status as one of the top performing schools in Northern Ireland.
It promotes "excellence, endeavour and empowerment" among its 1,000 pupilship, aged from 11-19.
The school had 100% of pupils achieving top marks - up from 96.5% and 95.3% per cent in the previous two years.
The school had 163 students in the year group and all scored at least three A*-C in A-levels or equivalent qualifications.
Principal of St Louis, Mr Sean Rafferty, commented: "“To say we as a school are delighted with last year’s public examination results would be an understatement.
"The whole St Louis Grammar school community is thrilled and the outstanding results really reflect both the positivity and the spirit of team work that we encourage at all times inside the class room and beyond.
"As a school we pride ourselves on ensuring our students gain successful outcomes at GCSE/GCE and this year once again we have surpassed those internal challenging targets with the 100 % figure.
"To have every student in sixth form leave St Louis with an exceptionally strong academic profile is a really huge advantage for them whether students decide to pursue high demand courses at university or follow the higher national apprenticeship route.
"Attaining these excellent results across such a large cohort of students in our U6 (163 students) and across a wide curricular offer, really reflects our academic strengths as a school.
"While this year’s results have been magnificent, we are also aware that over the last number of years SLG has been a top performing school in NI and that these results from our students merely consolidate our achievements of the past as well.
"Consistently outstanding academic outcomes such as these, over a number of years are the combination of engaged students, deep curriculum planning, high quality learning and teaching experiences for students, rigorous tracking of student progress, supportive parents and of course a superb teaching staff.
"As a school we are constantly monitoring and evaluating all aspects of curriculum delivery including engaging with our students regularly to ensure our students are not only achieving highly, but are both happy and enjoying their learning too.
"Good Governance, recent school investments in new pedagogies for the CPD of our staff, as well as recent DE capital investments have also contributed to the year on year academic success which has left our school well established as a top ranking school in NI and in the UK.
"All associated with the school are proud of our achievements to date and our teachers are privileged to be able to support our students, as they continue to achieve highly and are in strong positions to contribute to society in the future, through access to an exciting range of career pathways”.