The current study details the development and validation of a measuring instrument for the teachers' willingness to implement postmethod pedagogy principles in the Iranian context. Three postmethod components were identified after (1) undertaking a comprehensive review of the literature on the postmethod pedagogy and second language (L2) teacher education and (2) conducting interviews with domain experts and practicing language teachers. In Phase 1 of the study, an exploratory factor analysis (EFA) was conducted with a randomly selected and nationally representative sample (N = 255) of Iranian EFL teachers, resulting in three internally consistent factors: (a) Teacher Sense of Social Justice, (b) Teacher Autonomy, and (c) Teacher Sense of Academic Enthusiasm. In Phase 2 of the study, a confirmatory factor analysis (CFA) was completed with a new sample (N = 648) of practicing teachers. Strong model fit estimates in Phase 2 confirmed the factor structure of Phase 1 and resulted in a final 29-item scale called "Postmethod Scale" (PMS).