The present paper develops the familiar metaphor of teaching as performance towards a definition of teaching as performative act, where words and actions aim to effect cognitive, affective, and behavioral changes in learners. Through the lens of speech act theory, the author argues that teaching consists of pedagogical perlocutions—speech acts whose observed and unobserved effects on learners exceed authorial intention and scientific prediction. The author concludes by considering the ways in which these definitions of effects and effectiveness are themselves the performative effects of performance-based teacher assessment regimes.