By now the school had begun to feel a growing pressure and demand to convert the medium of instruction to English to enable its students to meet the challenges of the modern era. This change was introduced in 1979. In 1987, the school was brought under the umbrella of the Indian School system and was named as Indian School Muttrah.

The years have flown by since and the standard set by the school has seen the student strength grow each year. Prior to 1993 it was housed in buildings at different locations and the growing demand for admission began to strain its existing facilities.

It was therefore, decided in 1992 to shift the entire school to a larger and well designed building that would offer better facilities in terms of a large playground, spacious classrooms, laboratories, a hall and adequate space for administration offices.

In 1992 as the school was planning to add Grade VIII in the following year, an application for a composite affiliation to CBSE was also made. The rented premises of the school and its future plans for a state-of-the-art school building were inspected in November 1992 and the school was granted composite affiliation till Grade X for 1993 (vide C.B.S.E letter reference number CBSE/AFF/91/61304, dated 22-12-1992). The first batch of Class X students appeared at the AISS Examination of the C.B.S.E. in March 1996. It was upgraded to Senior Secondary School in 1999 and the first batch of Class XII students appeared at the Board examination in 2001.

The current building of the Senior School was constructed in 1993 and occupied in the beginning of the new academic year. As it is located in an area called Al Wadi Al Kabir, Indian School Muttrah was renamed Indian School Al Wadi Al Kabir as per the instructions of the Directorate of the Ministry of Education.

This building, apart from having spacious, airy and sunlit classrooms, also has all the facilities that are required of a modern school, like separate science laboratories, IT laboratories, ICT facilities in each classroom, a library, an audio-visual room, a multipurpose hall with facilities for indoor games, and adequate space for some outdoor games.

The number on roll has been steadily increasing each year and a part of the school was shifted to new premises with similar state-of-the-art premises. The pre-primary classes were shifted to their current premises in 1997 and Classes I to V in July 2000.

The school has currently 6303 students on roll.

The best asset of the school is its teachers; they form its backbone. All the teachers of the School are well qualified. To keep them abreast with developments in the field of education, frequent in-house workshops are conducted. Apart from these, in-service workshops by experts in different subjects are also periodically conducted. Some of these that have been held in the past few years were in Hindi, Mathematics and Social Studies at the Middle and the Secondary level, in Mathematics and Environmental Studies for Primary teachers and on Activity based approach for Kindergarten. Objective-based teaching and evaluation, Value Education in classroom are a few other topics. These staff developmental activities have enabled us to reorganize teaching to make it activity baseded and application oriented, with emphasis on the acquisition of self-learning skills by children. Methods of evaluation have also undergone a change in keeping with the current teaching-learning approach.