Historical Background Machakos girls' high school was started as a Primary School for boys under the name Government African School in 1915. In 1946, the Primary School became a mixed school for boys and girls. In 1950, the school was split and all the boys were moved to the now Machakos School. The school name changed to “Government African Girls Intermediate School.”
In 1959 the first Form 1 class of 12 girls was started and by the year 1960 the school had form 1 and 2 and standard 6,7and8. It's also the same year that the school changed its name to Machakos Girls High school.
In 1965 a double stream was introduced in form 1 class and in 1968 the whole school became a triple streamed school from form 1-4.
In 1972 a form 5 arts class was started and later in 1978 a second stream was granted but was changed to a science stream in 1984. In 2007 a fourth stream was introduced in form 1. Currently the school is an extra county six streamed boarding girls' school with an enrolment of 1000 students. The school has kept improving in academic and non-academic performance over the years. In 2016 K.C.S.E. results the school registered a mean of 7.98. Girls have maintained high discipline ever since