The aim of this research is to investigate preservice mathematics teachers' performances on systems of linear equations within the context of self-efficacy on systems of linear equations. The research uses a case study methodology which follows from the qualitative paradigm. 42 second year pupils from the department of primary mathematics education in 2009-2010 academic year were chosen for the study by using the convenience sampling strategy. Performance Test of Systems of Linear Equations was used to assess of the preservice mathematics teachers’ performances on solving systems of linear equations and Systems of Linear Equations Self-efficacy Test (m=n, m≠n) was developed and used to determine the levels of efficacy. In the analysis of the quantitative qualitative and data, inferential and descriptive statistics were used respectively. While the majority of preservice mathematics teachers showed medium-level performance, more than half of the participants had high-levels of self-efficacy. The presence of a significant positive medium level correlation between performance and self-efficacy is an indicator of the fact that self-efficacy affects performance.
