The purpose of the study is to analyze the attitudes of pre-service teachers towards mainstreaming before and after the informative studies about mainstreaming within the scope of special education courses carried out with primary mathematics pre-service teachers. The problem sentence of the study was determined as “What are the effects of informative studies regarding mainstreaming within the scope of special education courses carried out with primary mathematics pre-service teachers on the attitudes of pre-service teachers towards mainstreaming?” The design of ‘pretest-posttest with single group’ was used among quantitative data collection tools in the present research. This study was carried out with 38 pre-service teachers, 18 female and 20 male who are senior students in Marmara University, Educational Faculty, Teaching Primary School Mathematics Department in 2010-2011 academic years during fall semester. ‘Attitude Scale for Individuals who are affected by inabilities’ was used for the solution of the problems which was dealt with during the study. It was concluded that initially, people with disabilities were perceived as different from others by pre-service teachers, but then people with disabilities were not perceived as different from others by pre-service teachers. With this result, it is seen that the study which was carried out within the scope of special education course have a major role. It is concluded that the study increases the awareness level of students and change their point of views positively.