Various studies conducted into mainstreaming implementations in preschool and primary school but implementations in light of data are rare in the secondary schools. To provide valuable insights to this gap in the literature, the present study was conducted to identify the requirements in resource room implementations in a secondary school and demonstrate the contributions of the actions produced to improve the needs that were determined. The research was conducted as an action research. 12 mainstreaming students in 5th, 6th, 7th and 8th grade, 20 field teachers, three counselors, researchers and field specialists took part in the study. Data were collected using qualitative methods; interviews, observation, researcher notes, and documents. The data were analyzed with descriptive and content analysis. The research findings are explained under the following headings: needs assessment, preparation/implementation of the action plan and assessment after implementation. Our findings revealed that teachers had limited knowledge of teaching methods and on the implementation of teaching; they had high expectations from the students and because of the intensive curriculum, time was an important problem for the teachers. To meet the identified needs, an action plan that included the organization of RR and the on-the-job training of the teachers was prepared. During the implementation phase, a cyclical process of innovation and changes were followed. Following the implementation, the teachers and counselors evaluated the on-the-job training as being different from traditional in-service training and as an innovative education process that increased teacher-student motivation and participation.