The International School of Brussels (ISB)
🇧🇪 Brussels · Founded 1951 · IB / American · Ages 2.5–18
Reviewed by Priscilla Han · 2026-07-24
A well-established, accredited international school in Brussels offering an unusually broad set of graduation pathways, with strong third-party accreditation but no single graded public inspection band available in Belgium.
Curricula
IB, American
Age range
2.5–18
Languages of instruction
English, French, Dutch, Spanish, Japanese
Annual fees
Not published
Enrollment
1,300
Boarding
No (day school)
IB authorised
DP
Accreditations
Council of International Schools (CIS), Middle States Association (MSA-CESS), International Baccalaureate Organization (IB World School)
Tier Profile
We only tier dimensions backed by a public inspection verdict or verifiable accreditation. Other dimensions show a data flag — never a guessed score.
BrightKey's Assessment
The International School of Brussels (ISB) is an independent, not-for-profit English-language school founded in 1951 (originally the American School of Brussels), serving roughly 1,300 students from preschool through Grade 12 on its Kattenberg campus. English is the main language of instruction, with a French bilingual programme from Grade 5 and additional language offerings including Dutch, Spanish and Japanese. ISB is accredited by the Council of International Schools and the Middle States Association, and is an IB World School offering the IB Diploma alongside Advanced Placement, BTEC and a US High School Diploma.
Why These Ratings?
Inspection & AccreditationA — Excellent
Belgium has no single graded public inspectorate that publishes an Outstanding/Good band for international schools, so the rating is capped at A. Within that cap, ISB earns the top band on strength of verifiable dual accreditation (CIS and Middle States) and its long-standing status as an IB World School offering the IB Diploma.
Strengths & Trade-offs
Strengths
- Dual international accreditation — Council of International Schools (CIS) and Middle States Association (MSA-CESS) — plus IB World School status.
- Unusually broad range of high-school graduation pathways (IB Diploma, Advanced Placement, BTEC and a US High School Diploma).
- Long institutional history, established in 1951, and a large, diverse community of 1,300+ students from 60+ nationalities.
- Low reported student-to-teacher ratio (7:1) and dedicated Inclusion & Challenge support across all age groups.
Trade-offs
- Tuition and fees are not published on the publicly accessible pages reviewed, limiting cost transparency for prospective families.
- No single graded public inspection band exists for international schools in Belgium, so no external Outstanding-style rating is available.
- PYP and MYP authorization could not be confirmed from official IB or school sources at time of review (only the IB Diploma is verified).
Is It Right For You?
Best For
- ✓Internationally mobile families wanting choice among IB, AP, BTEC and US-diploma pathways at one school.
- ✓Students seeking an accredited English-medium education with structured additional-language and home-language options.
- ✓Families needing English-language development (EAL) or learning-support services.
Not Ideal For
- ✕Families requiring boarding, which is not offered.
- ✕Families who need a published, graded government inspection rating to compare schools.
- ✕Families needing tuition figures published upfront before enquiring.
Curriculum
English is the main language of instruction, with a French bilingual programme available from Grade 5 and French lessons from age 2.5. The school states it offers five high-school graduation pathways: the IB Diploma, Advanced Placement (AP), BTEC and a US High School Diploma. Only IB Diploma (DP) authorization is verified here; PYP/MYP authorization could not be confirmed from official sources.
Fees
Tuition and fees are not published on the publicly accessible pages reviewed; a Tuition & Fees page is linked from the school site but no figures were retrievable. Contact the school directly for current rates.
Admissions
ISB is an independent, not-for-profit school serving students from preschool (French from age 2.5) through Grade 12, organized into ECC (Preschool–Grade 2), Elementary (Grades 3–6), Middle (Grades 7–9) and High School (Grades 10–12). Inclusion & Challenge services provide personalised support across all age groups. Prospective families should confirm current entry requirements with the admissions office.
Campus Life
The school occupies a campus at Kattenberg 19, B-1170 Brussels, with a community of 1,300+ students representing 60+ nationalities and 55+ spoken languages, and 215+ teachers. Athletics are extensive, with the school reporting over 15 sports and 50 competitive teams.
University Placement
School-reported · not independently verified
University-destination and IB/AP results data were not published on the pages reviewed (school-reported, unverified). Contact the school for outcome statistics.
Sources
Every verifiable fact carries a public source — verify it yourself.
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