The International School Rheintal opened with 19 students and 7 teachers in August 2002, with grades 1 to 7. By the end of the school year there were 26 students.

The second school year started with 54 students and 12 teachers. Kindergarten for 3-6 year olds and grade 8 were added. By the end of the school year there were 56 students.

The third school year started with 64 students and 13 teachers. Grade 9 was added.

In the fourth year Grade 10 was added and the 3-6 year-olds were split into 2 groups: Pre-school for 3-4 year-olds and Kindergarten for 5-6 year-olds. The school year started with 84 students. During the 2005-2006 school year ISR was authorised to offer the International Baccalaureate Primary Years Program and also authorised to offer the IB Diploma Program from August 2006.

In August 2006 the school added Grade 11 starting the IB Diploma Program. The number of students had increased to 112. Kindergarten became a full time program.

Grade 12 was added in the 2007-2008 school year. The school opened with 121 students. In May 2008 ISR had its first High School Graduation Ceremony with 5 graduates.

In 2008-2009 the school year opened with 130 students. A new 2 story container building was constructed over the summer to accommodate the growing numbers. A larger playing field also became available to the ISR students.

The 2009-2010 school year saw the addition of a full time counselor & learning support specialist and the graduation of four IB Diploma graduates.

In 2010-2011 the sail was added. We celebrated our largest ever graduating class of 9 students, 6 of whom gained more than 32 IB Diploma points; 1 student achieving the maximum 45 points available!

In 2011-2012 ISR invested heavily in a revamp of the ICT system. New computers and IPads were bought and beamers were added to all teaching rooms.

At the start of the 2012-13 academic year ISR celebrated its 10 year anniversary. 9 students graduated.

The school year 2013-2014 started with a 140 students and numbers grew to 150 by the end of the school year. The Early Years Program is now called Kindergarten 1, 2 and 3. The school had a preliminary accreditation visit by the Council of International Schools and gained candidate status for accreditation. 9 students graduated.

For the 2014-2015 school year a new art room has been set up in the spectrum and the computer room moved to beside the library. An outdoor classroom was installed in the garden. In January ISR started working with International School St.Gallen.

In 2015-2016 our IT was moved to the Cloud. Connections with ISSG became stronger with classes now taking field trips together and teachers collaborating regularly. The focus for the year was preparation for the CIS Accreditation visit at the end of April. The MYP was re-evaluated. In June 2016 the school was accredited by the Council of International Schools.

For the 2016-2017 school year, the school has upgraded the wifi throughout the school.  Kindergarten 1/2/3 are now taught together for most lessons.
The MYP and DP were successfully re-evaluated. Security Cameras and lights were installed throughout the grounds of the campus.

For the school year 2017-2018 Kindergarten got a new shed and mud kitchen. The school year started with 125 students.

During the 2018-19 school year an outdoor learning space was being developed with work beginning on a sensory path. The teachers began the year with a workshop on the United Nations Sustainable Development Goals and started to consciously bring these ideas into their lessons. The school also made efforts to reduce use of plastic and waste – particularly with water and at school events. In May the Hilti Family Foundation announced they would build a new building and gymnasium for the International School Rheintal – to be located on the vacant land near the current campus and to be completed by 2023.

For the start of the 2019-20 school year, the outdoor learning center was further developed – the sensory path was completed, a music wall and water wall were added for students to experiment with sound and water flow, and the mud kitchen was further developed by a parent. Apple TVs were installed throughout the school.