This study identified the reasons why people codes-switch, studied the influence parents, teachers and peers had on the code choice of students and recommendations were given to solving the problems of codes- switching. Questionnaires were administered on two hundred (200) students, fifty from each school who are predominantly speakers of Yoruba language and they were randomly drawn from SSS1to SSS3 of the following schools: Saint Magarets School, Ilesa, Ilesa Grammar School, Ilesa, African Church Grammar School, Ilesa, and Saint Lawrences Grammar School, Ilesa. The result on the test of educational background revealed that students with sub-standard educational background use code-switching more than those with standard educational background. Another fact revealed was that nearly all the teachers that were involved in the research do code-switch. And lastly it revealed that the language individuals speak at home has tremendous influence on them. The study concluded that students should be warned about the danger inherent in switching if made to become a habit and that students should be discouraged in the use of switching in informal settings so as to facilitate the free flow of communication between or among the speakers.