There are not many options for international schools in Madrid. We decided for ICS but not 100% satisfied with the experience. There wasn’t a big offer of sports of activities and we missed a bit of rigour.
Our experience was from 2009. Though a great school for International short-stay students, due to its openness, flexibility, welcoming….for longer-staying students we found that it lacked a solid base. We were disappointed with foreign languages other than Spanish and English, the handling of high-capacity students, and the lack of academic rigor (leading to a class graduating with a missing subject). As a general rule, teachers’ level was fairly high but we did have cases of serious underperformance.