The general purpose of this study is to examine the effect of the feedback given to prospective teachers working with students with severe and multiple disabilities on collaborative working skills. Collaborative working skills, which are based on a collaborative approach, include the process of sharing knowledge, skills, and responsibility of two educators working in the same classroom environment. In order to develop collaborative working skills of the educators working together, they should work together in the planning and continuity of the whole teaching process. This skill starts to develop in accordance with the experiences of the prospective teachers in the real classroom environment and the feedback given to these experiences and consolidates with the frequency of in-class practices. This study, which examined the effect of the feedback given to prospective teachers to gain them cooperative working skills, was conducted with 12 prospective teachers who will teach in the classes of students with severe multiple disabilities (SMD) in Ankara province in the 2017-2018 academic year. The research was planned according to one-group pretest-posttest design, which is one of the pre-experimental designs. In this context, the first course practices of prospective teachers who practiced with students with severe multiple disabilities with their partners in the classroom environment were recorded by the prospective teachers; and after the records were watched by the practice advisor, the checklist was prepared and performance-based feedback was given to each prospective teacher. The second courses given after receiving the feedbacks were similarly scored and the results were analysed in accordance with the research method. Results show that there is a statistically significant difference between pre-test and post-test scores of prospective teachers before and after taking performance-based feedback on collaborative working skills. The findings of the research were discussed within the framework of the literature and suggestions for practices were given.