The school became established when the Ghanaian Secretary of the Ministry of Education at the time, Ama Atta Aidoo, sought to alleviate the problem of high boarding fees and wanted to increase the enrollment of students in day schools. Chemu also met with the increasing demand of vacancies in secondary schools in the Tema Township, situated in the Greater Accra Region of Ghana; hence the conversion of the Community 4 No. 2 Middle School into a model day secondary school known as Tema Day Secondary school. The school has a legacy of eight (8) classrooms, along with the motto ‘Discipline and Hard work’. The school was formally opened on 12 October 1982 with a double stream of 86 students and a teaching staff of nine (9). The then-assistant headmaster of Tema Secondary School, late Mr. P.K. Dzitri was seconded to the school as Acting Headmaster, in 1982. In the same year the Assistant Bursar of Tema Secondary School, Mr. Gilbert Kpelende was also seconded to the school. The first batches of students were, therefore, remnants of the Common Entrance candidates of Tema Secondary School, since the name of the school was not on the Common Entrance List. A few students entered into the addition through a late entrance examination conducted by the school. Following an appeal from Tema traditional council, the name of the school changed from Tema day school to Chemu secondary school. Attempts were made to have the name of the school changed in the early nineties to Adjetey Ansah Secondary school, but this did not materialize due to stiff opposition from some quarters, including the Students’ Representative Council.