The study investigated code-switching and its implications for teaching Mathematics in selected primary schools in Ile-Ife. The data for the study were obtained from five mathematics teachers and fifty pupils from five purposively selected primary schools through ethnographic observation and structured interviews. Data collected were analysed using Myers-Scotton’s Matrix Language Framework model, as well as descriptive and inferential statistics. The results showed that teachers in the schools used code switching as an approach to the acquisition of literacy in that it allowed each pupil to use each of his/her languages in a natural, meaningful way as the various classroom activities were being implemented. The study concluded that the use of code switching in multilingual mathematics classrooms does not result in a deficiency in learning, but is a useful strategy in classroom interaction and efficient way of transferring knowledge to students.