The purpose of this study was to investigate how preschool instructors use social media for professional development. Explanatory sequential design, one of the mixed research methods, was used in the research. The quantitative study group of the research consists of 213 preschool teachers working in Kahramanmaras province in the 2020-2021 academic year, and the qualitative study group consists of 16 preschool teachers. "Social Media Usage Questionnaire" and semi-structured "Interview Form" were used as data collection tools in the research. For the analysis of quantitive data in the study, frequency, percentage and arithmetic avarages were calculated using the SPSS 21 package program. Content analysis was used in the analysis of qualitative data. It was determined that teachers find Instagram, Youtube, Whatsapp and Pinterest useful in terms of their professional development. It has been found that social media helps teachers to see things from multiple viewpoints, keep up with innovations, access diverse activities, advance their knowledge and abilities and access activities for all developmental domains. It has been determined that teachers share their posts on social media in order to be useful for their collegues and for informational purposes It was concluded that the use of social media facilitated the implementation of the preschool education program and enriched the learning environment.