Purpose: The study begins by defining and conceptualizing Transformative Leadership Conversation (TLC). The conceptualization addresses the meaning of transformation, sensemaking and learning dialogue, and the conversation structures of framing, questioning and listening, and affirming. Next, the authors build a theoretical argument from self-determination theory on the function of TLC. The study concludes with an empirical test of the structure and function of TLC. Design/methodology/approach: There were two parts to the empirical study. First, the authors designed and tested a scale to measure TLC by its structural features (e.g. questioning, listening and affirming language). Second, the authors used a correlational design with ex-post facto data to test the primary assumption that TLC activates autonomous motivation and action. Data came from a random sample of 2,500 teachers in a southwestern state. Useable responses were obtained from 1,615 teachers, for a response rate of 65%. Findings: The empirical tests reveal that the 12-item and 6-item measure of the School Leader Transformative Conversation Scale present valid and reliable evidence on the frequent use of TLC. Consistent with the hypothesized model, TLC had a direct, positive relationship with teacher vitality. It also had a negative relationship with autonomy frustration and a positive indirect effect on teacher vitality by reducing the negative effect of autonomy frustration. Originality/value: TLC advances a new conceptual lens to study school leadership as a discursive process. The concept opens lines of inquiry that have not yet been examined in school settings.