The purpose of this study is to evaluate the effects of Instructional Technologies and Material Design (ITMD) course on pre-service mathematics teachers’ attitudes, efficacy beliefs about using concrete materials, and their opinions regarding the material preparation process. A total of 73 pre-service teachers were participated in this study. The scale developed by Bakkaloglu was used to determine efficacy beliefs of pre-service teachers about using concrete materials, and the attitudes scale developed by Cetin, Bagceci, Kinay and Simsek was used to determine the attitudes towards ITMD course. A written form was also used to reveal the opinions of pre-service teachers regarding the material preparation process. The qualitative data collected from 16 pre-service teachers was analyzed with the MAXQDA. Using content analysis, codes and themes were created separately by the researchers and analyzed through several iterations. As a result of this study, positive changes were found in the attitudes and efficacy beliefs of pre-service teachers. The results obtained from the opinions of the pre-service teachers support this positive change. In other words, it is possible to argue that the attitudes of pre-service teachers towards the material development process changed positively with the positive change in the efficacy beliefs about preparing materials after taking the ITMD course.