Alliance High School emerged the best school in the KCSE 2021/2022 exams in the County with a mean score of 10.19 which is a B+ (plus).
2021/2022 BEST, TOP PERFORMING SCHOOLS IN KIAMBU COUNTY
| Pos Nationally | School Name | Mean Score | County | |
| 4 | Alliance High School | 10.19 | B+ | Kiambu |
| 9 | Mary Hill Girls High School | 9.512 | B+ | Kiambu |
| 73 | Starehe Girls Centre | 8.23 | B- | Kiambu |