The research reported in this paper is based on an exploration of the ways in which student teachers learn about the issues and concerns that shape their own professional learning. Shulman's process of pedagogical reasoning and action was used as a conceptual framework to systematically elucidate different critical incidents that student teachers experienced and to then apply it as an analytic framework for developing deeper understandings of the complex task of learning to teach primary science. Primary science student teacher participants (n = 22) were stimulated to reflect upon critical incidents in order to facilitate identifying their teaching concerns and teaching needs. The results indicate that by helping student teachers to focus on critical incidents in their learning to teach, they come to question their practice more deeply and, through such reflection, gain new insights into teaching as being problematic. (Contains 1 figure and 1 table.)