This article examines how and under what conditions a new pedagogy can spread at scale using the Learning Community Project (LCP) in Mexico as a case study. Started as a small-scale, grassroots pedagogical change initiative in a handful of public schools, LCP evolved over an 8-year period into a national policy that spread its pedagogy of tutorial relationships to 9000 schools. The author conceptualizes large scale pedagogical transformation as a process of widespread cultural change that occurs when a new pedagogy developed by a critical community is adopted by movements who disseminate it in three arenas: the social, political, and pedagogical arenas. The author examines the scale reached by LCP relative to the dimensions of spread, depth, ownership, and sustainability proposed by Coburn ("Educ Res 32"(6):3-12, 2003). It then extracts seven principles to change pedagogy at scale: 1) Turn 'disadvantage' into possibility; 2) Establish a clear purpose centered on student learning and a compelling vision of effective pedagogy; 3) Directly change the instructional core; 4) Create multiple opportunities to observe, practice, and refine the new pedagogy; 5) Attract the support of system leaders, or become one; 6) Change the surrounding institutional environment from the inside out; and 7) Keep a strong link between design and execution.