Preservice teachers will soon be expected to manage a classroom of students who will have myriad peer relationships and social issues among themselves. Managing these classroom social dynamics is increasingly recognized as an essential component of teachers' classroom management practice. One way to support teachers in this skill is to bolster their knowledge of development, particularly during initial preparation programs as preservice teachers. To better understand how developmental knowledge may relate to preservice teachers' beliefs about social dynamics management, we assessed their attitude towards developmental knowledge (i.e., how important developmental knowledge is to their teaching practice) and their degree of preparation in development during their initial teacher education program. We examined associations between these constructs with two key indicators of beliefs about social dynamics management: (1) their attitude towards social dynamics management and (2) their self-efficacy for social dynamics management. Using a correlational research design, we examined these relations in a sample of n = 266 (86% female) preservice teachers who provided survey data on these constructs. Several additional covariates were considered in analyses (e.g., internship experience). Results indicate that preservice teachers' attitude towards developmental knowledge and perceived preparation were related to self-efficacy for social dynamics management. Only attitude towards developmental knowledge was related to attitude towards social dynamics management. Implications for infusing developmental knowledge and preparation in teacher education programs are discussed.