Numerous studies have attempted to explain the role of social networking platforms within educational environments, though none of them has reported on their potential for enhancing professional development in education. The purpose of this qualitative research was to explore the reflections of prospective teachers who were assigned to design and conduct instruction on Facebook. Seven groups of prospective teachers (n=25) attending a teacher training program in Turkey participated in the study. Reflections of these prospective teachers on online teaching through Facebook were elicited by means of reflective papers. As an outstanding result of the online teaching project in the current study, the prospective teachers gained positive experiences in utilising Facebook for designing and implementing online teaching activities that are in accordance with the constructivist learning paradigm. However, sustaining learner involvement, enhancing interaction, and problems resulting from group work processes were observed as destructive issues throughout the online teaching project.