The purpose of this study was to determine the level of self-efficacy of prospective mathematics teachers (PMTs) on the competency "planning and organizing instruction" that is one of the teacher competencies identified in 2009 by Ministry of Education. The sample of this study consists of 111 total prospective teachers (PTs) study in mathematics department of Faculty of Science and Faculty of Education, in Inonu University, in Turkey. To determine the level of self-efficacy on teacher competencies of PMTs, "Scale for Self-efficacy on the Competence of Planning and Organizing Instruction" was prepared and used by researcher. "Subject-Specific Competencies" published by Ministry of Education (2009) was used to prepare the scale. In this study, the levels of self-efficacy of PMTs on planning and organizing instruction and the variables that affect the levels were tried to determine. According to data, the level of self-efficacy on teacher competencies of PMTs both is adequate and has some differences in terms of some demographical variables. In addition, a few new teacher competencies were identified by researcher using the PMTs' views