The purpose of this study is to detect whether primary and secondary schools teachers' attitudes and self-efficacy differ according to certain variables regarding mainstreamed education and determine the relationship between them. Quantitative method is used in the survey of the scanning model. The sample of the research is a total of 310 teachers, including 251 class and 59 science teachers, which are working in foundation and private primary and secondary schools. The teachers who have participated in the study are 197 women and 113 men. In the study, “Personal Information Form” consisting of 17 substances, “The Teacher Self-Efficacy Scale in Science Education for Mainstreamed Students”, consisting of 21-items, with the Cronbach alpha coefficient .94 and "Attitude Scale Towards Mainstreaming", consisting of 30 substances, with the Cronbach alpha coefficient .92. Responses obtained from the sample group have been analysed by coding in SPSS 22 program. As a result of the study, when the attitudes and self-efficacy of teachers in science education for mainstreamed students are evaluated, it is found that their self-efficacy levels are high and their attitude levels are above the mid-level. In addition, when the correlations between dependent variables are examined, it is determined that there is no meaningful relationship between teachers' self-efficacy levels and attitude levels in science education for mainstreamed students.