Effective classroom discourse is a critical yet complex component to learning science [Achieve. (2013). "Next generation science standards: For states, by states." The National Academies Press]. This study focuses on the abilities of Elementary pre-service teachers (EPSTs) to lead effective science discourse as they plan, implement, and evaluate their own science talks to a small group of peers. We collected and analysed sixty-three transcribed talks from a physical science course taught to elementary education students. A codebook for analysing talk moves used in science discourse was developed and used to analyse 4287 talk moves. Frequency of moves and patterns in their use were noted. Most frequently used moves made by EPSTs demonstrate their reliance on providing information and asking literal (recall) questions; whereas they used significantly fewer moves that promoted deeper engagement with content (Uptake, Push-back and Connections). Implications on teacher preparation programmes are explored, in particular how this approximation of practice could be implemented to improve discourse skills in pre-service teachers of elementary science.