Here is list of extra county schools in Kitui County;
NO. |  KNEC​​ CODE | EXTRA COUNTY | TYPE | CLUSTER |
| 13302102 | ST CHARLES LWANGA SCHOOL | Boys | C1 |
| 13302103 | ST. ANGELA’S GIRLS SECONDARY SCHOOL | Girls | C1 |
| 13302108 | ST.MONICA GIRLS MULUTU SECONDARY SCHOOL | Girls | C1 |
| 13310102 | MWINGI SECONDARY SCHOOL | Boys | C1 |
| 13317101 | MUTOMO GIRLS SECONDARY SCHOOL | Girls | C1 |
| 13328101 | KYUSO SECONDARY SCHOOL | Boys | C1 |
| 13331201 | MUTONGUNI SECONDARY SCHOOL | Boys | C1 |
| 13331205 | KYONDONI GIRLS SECONDARY SCHOOL | Girls | C1 |
| 13339102 | MIGWANI SECONDARY SCHOOL | Boys | C1 |
| 13339107 | KYAMBOO SECONDARY SCHOOL | Mixed | C1 |
| 13339204 | THITANI SECONDARY SCHOOL | Girls | C1 |
| 13344101 | ST LUKES YATTA SECONDARY SCHOOL | Boys | C1 |
| 13351102 | CHULUNI GIRLS’ SECONDARY SCHOOL | Girls | C1 |
| 13353201 | MULANGO GIRLS HIGH SCHOOL | Girls | C1 |
| 13353301 | MALIKU GIRLS’ SECONDARY SCHOOL | Girls | C1 |
| 13354101 | KISASI SECONDARY SCHOOL | Boys | C1 |
| 13354201 | MBITINI GIRLS’ SECONDARY SCHOOL | Girls | C1 |
| 13357101 | IKUTHA BOYS SECONDARY SCHOOL | Boys | C1 |
| 13360101 | MATINYANI SECONDARY SCHOOL | Boys | C1 |
| 13302107 | ST URSULA GIRLS’ SECONDARY SCHOOL-TUNGUTU | Girls | C2 |
| 13310103 | YAMBYU GIRLS SECONDARY SCHOOL | Girls | C2 |
| 13310201 | WAITA SECONDARY SCHOOL | Mixed | C2 |
| 13331204 | KATHEKA BOYS’ SECONDARY SCHOOL | Boys | C2 |
| 13332102 | A.I.C SOMBE GIRLS SECONDARY SCHOOL | Girls | C2 |
| 13338202 | ST. TERESA’S UKASI GIRLS’ SECONDARY SCHOOL | Girls | C2 |
| 13339101 | A I C KYOME BOYS SECONDARY SCHOOL | Boys | C2 |
| 13339103 | A I C KYOME GIRLS SECONDARY SCHOOL | Girls | C2 |
| 13339105 | NZAUNI SECONDARY SCHOOL | Mixed | C2 |
| 13339106 | ITOLONI GIRLS SECONDARY SCHOOL | Girls | C2 |
| 13339108 | MUSUANI SECONDARY SCHOOL | Mixed | C2 |
| 13339201 | NGUUTANI SECONDARY SCHOOL | Boys | C2 |
| 13339301 | NZELUNI GIRLS SECONDARY SCHOOL | Girls | C2 |
| 13357102 | IKUTHA GIRLS SECONDARY SCHOOL | Girls | C2 |
| 13365101 | MUTITO BOYS SECONDARY SCHOOL | Boys | C2 |
| 13365102 | ST. MARY’S MUTITO GIRLS SECONDARY SCHOOL | Girls | C2 |
| 13366101 | GANKANGA SECONDARY SCHOOL | Mixed | C2 |
| 13302105 | ST THOMAS AQUINAS KALAWA BOYS | Boys | C3 |
| 13328102 | KIMANGAO GIRLS SECONDARY SCHOOL | Girls | C3 |
| 13351101 | ST.PETER’S NZAMBANI BOYS SECONDARY SCHOOL | Boys | C3 |
| 13353102 | ITOLEKA SECONDARY SCHOOL | Girls | C3 |