The goal of this study was to inquire the impact of the reflective coaching (RC) on development of pre-service EFL (English as a Foreign Language) teachers' sense of efficacy and instructional skills. The reflective coaching program utilized in this study was developed and adapted by the researcher in 2016 mainly based on the theoretical views and principles of reflection, self-analysis of strengths and weaknesses and the writing of personal statements, and reflective teaching. The research approach used for this study was both quantitative and qualitative and this study is a single case study based on pre/post-test design. To achieve this goal, eight volunteer male and female (one male and seven female) undergraduate students, aged from 21 to 22, attending B.A. program in ELT, Faculty of Education, Çanakkale Onsekiz Mart University, Turkey participated in the study. For the pre/post-test design of this study, one case study group was formed. The study was conducted between February 11, 2019 and May 17, 2019. During the implementation of the RC program, the researcher also employed an overview of the instructional skills, which represented teaching behaviors desired. Results showed significant differences in favor of the implementation of RC program on development of pre-service EFL (English as a Foreign Language) teachers' sense of efficacy and instructional skills. The findings are expected to have implications for how reflective coaching can be a means to improve instructional skills and sense of efficacy and recommendations for EFL teachers and curriculum designers will also be made.