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 storey container building was constructed over the summer to accommodate the growing numbers. A larger playing field also became availible to the ISR students.