These Proceedings are a written record of the research presented at the 33rd Annual Meeting of the North American Chapter of the International Group for the Psychology of Mathematics Education (PME-NA 2011) held in Reno, Nevada, October 20-23, 2011. The theme of the conference is Transformative Mathematics Teaching and Learning. The Proceedings include papers from 3 plenary sessions, 69 research reports and posters, and 13 working and discussion groups. Papers from the research reports, brief research reports, and posters are organized into chapters by topics. Chapters include the following: (1) Advanced Mathematical Thinking; (2) Affective Issues; (3) Algebraic Thinking; (4) Classroom Discourse; (5) Elementary Education; (6) Equity and Diversity Issues; (7) Gender; (8) Geometry; (9) Middle School Education; (10) Probability and Statistics; (11) Problem Solving; (12) Rational and Whole Numbers; (13) Reasoning and Proof; (14) Research Methods; (15) Secondary Education; (16) Teacher Beliefs; (17) Teacher Education: In-Service/Professional Development; (18) Teacher Education: Preservice; (19) Teacher Knowledge; and (20) Technology. Individual papers include references. [Individual plenary and research papers are available in ERIC.]