This study uses the self-determination theory to explore how personal characteristics, motivation and learning environment influence students' attitudes toward the learning of mathematics. The study adopted a sequential mixed methods design, with 360 students from 24 schools, constituting the sample for the study. The results revealed that in general, students have positive attitudes toward the learning of mathematics, and this could be attributed to the utilitarian motive of mathematics and its importance in daily life. Pearson Moment Correlation and independent T-test analysis were used to ascertain if there is any relationship between students' attitudes toward mathematics and their academic performance and the relationship between performance and school location. Also, the results from the interviews revealed a direct relationship between personal characteristics, motivation, learning environment and students' attitudes toward mathematics, as motivated students, and experience positive learning environments performed better. Based on the findings, we recommend that teachers and educational authorities ought to be innovative in using creative approaches that will motivate students in developing a more positive attitude toward the learning of mathematics as this is very crucial in our quest for improving students' performance in mathematics.