This research aims to test the effectiveness of the Competency Enhancing Training Program for Teachers Working with Students with Reading Disabilities (OG & Ouml;YEP), which was developed to increase the knowledge and proficiency of teachers working with students with reading difficulties, depending on the needs of the students in improving their reading skills. The research was designed using the exploratory sequential mixed method design, which is one of the mixed method designs. First, the needs of teachers in the training program were identified, and then the effectiveness of OG & Ouml;YEP was tested. Twenty classroom teachers for the needs analysis in the qualitative dimension of the research, thirty-two classroom teachers in the quantitative section, sixteen being in the experimental group and sixteen in the control group, participated in the study. As a result of the needs analysis, it was seen that teachers needed support in the methods, techniques and strategies that students with reading difficulties can use to improve their reading skills. OG & Ouml;YEP, which was developed to meet these needs of teachers, includes four units: pre-reading, during reading, post-reading and methods, techniques and strategies that can be used throughout the reading process. OG & Ouml;YEP was organized with four lecture sessions each week and continued for four weeks. The research results showed that the teachers in the experimental group of OG & Ouml;YEP increased their knowledge and competence in improving the reading skills of students with reading difficulties. Social validity findings revealed that teachers found the training program effective and efficient.