Educational reforms during the last decade have led to a more inclusive environment for students with different needs and have placed demands on teachers' readiness to instruct diverse students in the general classroom. Previous research has ascertained that student achievement is correlated with teacher quality and teachers' efficacy beliefs. Today, basic competence in mathematics is more important than ever for managing routine day-to-day activities and therefore, identifying and educationally supporting students with low performance in mathematics is necessary. The aim of the study was to investigate the perceived teacher efficacy beliefs of special education and mathematics teachers when teaching mathematics to low-performing middle school students. Results indicated that special education teachers had higher teacher efficacy beliefs than mathematics teachers. Teacher experience, certification or gender had no effect on teachers' efficacy beliefs. Furthermore, subject teachers reported high pedagogical knowledge for teaching low-performing students, and special education teachers reported having moderate mathematical subject knowledge.