Preservice teachers prepare for a profession that requires intense communication and interaction. They are expected to gain competencies in their profession in this process. These competencies include the technical knowledge particular to the profession, and communication and social skills. It is thus important to investigate the factors that affect the academic and social interaction, the learning environment and the psycho-social development of university students, and in particular, preservice teachers. This study aims to investigate the relationship among preservice teachers' social support perceptions, interaction anxiety and smartphone addiction. The students from the faculty of education and the students with the pedagogical formation training in Inonu University during the 2017-2018 academic year constituted the population of the study and the participants were 496 preservice teachers who were selected from this population using the random sampling technique. Hypotheses were developed to investigate the relationship among the research variables. After testing the hypotheses, the results indicated that the preservice teachers' social support perceptions and interaction anxiety significantly predicts their smartphone addiction, that their social support perceptions significantly predict their interaction anxiety, and that their interaction anxiety has a mediator effect on the relationship between their social support perceptions and smartphone addiction.