School students should not sit exams before fifth year, according to a major report on the future of the qualifications system.
The report also argues that a wider range of assessment measures should be used for Highers and Advanced Highers.
The review was carried out for the Scottish government by one of Scotland's leading experts on education Prof Louise Hayward.
The Scottish government said it would carefully consider the report.
It added that it would respond fully in due course.
Education Secretary Jenny Gilruth said: "I am very grateful to Professor Hayward and members of the review group for the time and effort they have given to bring this report together.
"These recommendations for reform could amount to a radical shift in Scottish education. As cabinet secretary I need to be certain that these changes are the right ones for Scotland's young people - and I am determined that the voices of teachers will be central to this process."