The present study aimed at developingreflective thinking skills among EFL prospective teachers through Facebook- delivered writing activities. The design of the present study was a pre-post, one experimental group. The participants of the study were forty-five EFL prospective teachers (Primary Education) at Faculty of Education, Aswan University. The present study used the reflective thinkingscale, developed by the researcher, as an instrument for assessing the participants' EFL reflective thinking skills. Participants were asked to practice writing activities and tasks delivered through a Facebook group “Think and Write" which created for the purpose of the current study. Data were collected and participants' scores in the reflective thinkingscale were used as measures of their development in reflective thinking skills. Results revealed that the participants' reflective thinking skills were developed as a result of participating in the Facebook group. Accordingly, the Facebook- delivered writing activities were found to be effective in developing reflective thinking skills among EFL prospective teachers.