The International Baccalaureate (IB) is to be introduced at Guernsey Grammar School and Sixth Form Centre.
The IB Diploma, which is recognised around the world, will be available in addition to the full range of A-Levels currently offered.
It is designed as an "academically challenging, broad and balanced" programme which prepares students for university and beyond.
The two-year course will start at Guernsey Grammar in 2012.
Head teacher Jeff Smith said: "One of our aims is to guide and nurture individual development and the IB Diploma provides a different approach to post-16 qualifications."
The school will hold an information evening on Tuesday 30 November to provide details about the IB Diploma programme.
Tina Watson, sixth form director, said: "Those students who started Year 10 in September this year will be the first cohort who will be able to choose to study the IB Diploma Programme in Guernsey as an alternative to A Levels.
"We want to make sure that all students and their parents have enough information about the options available before making any decisions."
IB was founded in Switzerland as a non-profit educational foundation in 1968.
It has grown in popularity in the UK and is now offered in more than 200 schools.