Oxford AQA has cancelled its A-level and international GCSE tests that were due to be held this summer.
The major UK examination board said it would have been impossible to go ahead as planned because of the Covid-19 outbreak.
Weeks ago, UK Cabinet Office Minister Michael Gove announced that board exams, including GCSEs and A-levels, would be cancelled this year.
Pupils in the UAE will be affected by the decision as many sit a combination of GCSEs and International GCSEs, A-levels and International A-levels.
Sadie Visick, managing director at Oxford AQA, said: "I am writing to you to announce the cancellation of the May/June 2021 exams, and confirm that Oxford AQA students will receive teacher assessed grades, in line with students in England.
"We have taken this difficult decision in order to end the uncertainty following the recent announcement of the cancellation of exams in England by the UK Government.
"OxfordAQA’s international GCSE and A-level exams are benchmarked to UK standards, and maintaining fairness and consistency in the grades provided to all students, in all countries around the world, is a priority for us."
Schools have been assured they will be supported to assess pupils accurately and fairly.
Brendon Fulton, principal at Dubai British School Jumeirah Park, said the Oxford AQA examinations were extremely popular in the UAE and used widely by schools.
Pupils at his school will be affected by the decision.
“We do some GCSE and some IGCSE examinations so previously, pupils had half of their exams cancelled," he said.
Mr Fulton is now waiting to see if Cambridge Assessment International Education, another popular examination board, will cancel its summer test series too.
A Gems Education representative said their schools would be offering guidance and assistance to all pupils affected by the decision.
"We continue to be in close, regular contact with all relevant exam boards to ensure our pupils and their parents are well informed and fully supported as this situation develops."