Background: Generalist teachers' confidence, competence and preparedness to teach Physical Education (PE) following Primary School Physical Education Teacher Education (PSPETE) has emerged as a research imperative. Yet little is known of teachers' perceptions of such matters. For teacher educators responding to the deficient delivery of primary school PE by generalists, greater understanding of these perceptions would be valuable. Purpose: To offer an empirically founded description of "perceptions of preparedness to teach primary school PE" that firstly informs ongoing deliberations for how generalist teachers may be prepared and secondly generates new ideas for teacher education (TE) research, pedagogy and practice. Participants and setting: Participants (n = 400) were pre-service generalist teachers finishing units of study in PE within several Primary School Teaching degree programmes at one Australian university. The setting for this research was unique as subject specialisations were a feature of generalist TE programmes. Data collection: Transformative Learning Theory underpinned the development of the data collection instruments. A survey was administered to participants (n = 400). Survey items employed Likert scales and free-response questions to collect data related to experiences of school-based PE and learning-to-teach PE. Subsequently a purposive sample of participants (n = 19) with different levels of specialisation were interviewed to examine (a) conceptions of primary school PE; (b) feelings, thoughts and beliefs associated with teaching that conception of PE and (c) future intentions. Data analysis: Survey data were analysed with SPSS to report descriptive statistics pertaining to univariate frequency distribution of item variables together with association and strength of association when item variables were placed in crosstabulation. Interview data were analysed using procedures described by Colaizzi to identify fundamental structures. The text-mining software, Leximancer, was used to identify theme clusters. Findings: Participants' perceptions of preparedness to teach primary school PE conformed to two meaning-making structures of Transformative Learning Theory. Conceptualising "self" in association with the subject was Habit of Mind whilst levels of preparedness was a Point of View. The composite of these structures was named a Professional Frame of Reference. To facilitate the reporting of these findings, the metaphor of a triple-folding lens was used to show "what" transformed, namely, participants' conceptions of primary school PE then associated roles and responsibilities. Conclusions: "Perceptions of preparedness to teach" are professional frames of reference. The triple-folding lens illustrates the multi-faceted dimensions of these frames. An additional outcome of the research is an empirically founded tool to underpin the design of a transformative pedagogy for PSPETE, a design whereby students' preparedness to teach is associated with a re-envisioned, more informed conception of school PE.