There are different opinions and individual teachers' beliefs about mathematics teaching. Teaching is a complex task shaped by many external and internal influences, including the beliefs held by individual teachers. The present study has looked into the existing relationship between teachers' beliefs about mathematics and their teaching practice in the classroom. It also aimed to understand what were the teachers' beliefs about mathematics and about mathematics teaching, which they used to define their practice in classroom. The participants were two mathematics teachers of primary and lower-secondary, from a private school in Karachi city. This study has found that teachers refers to a variety of aspects about mathematics and its teaching. However, the findings indicate that the beliefs focus on two key aspects; teachers' transmission of knowledge and teachers' personal experience about teaching and learning mathematics. The ways in which these issues influence teaching and learning of mathematical concepts at hand is considered. The nature of teachers' beliefs and the ways in which they influence their practice is questioned. Additionally, it was of particular importance to compare and contrast the beliefs of participants in order to gain knowledge about their understanding of mathematics in relation to the context in which the experience took place. Because of the existing teachers' beliefs, teacher educators and teacher education programs could consider alternative ways of thinking about and addressing beliefs, particularly the potential of building on rather than tearing down pre-existing beliefs. The improvement of mathematics teaching and learning in our schools will be guided by the findings from the present study and through the ongoing assessment of school mathematics programs.