Physical education is critical to addressing childhood obesity, yet many school-based programs do not meet established quality standards and teachers are called upon to change. Little is known about how change is initiated and its associated internal and external factors. Purpose: The purpose of this study was to investigate physical education teacher change that was self-initiated and externally initiated and to examine dispositions toward the change process relative to initiation. Method: A random national sample of physical educators representing each SHAPE America--Society of Health and Physical Educators regional district participated in a survey measuring past programming changes, primary initiators of change, and teachers' dispositions toward change. In total, 2,423 teachers (46% response rate) completed electronic, paper, or telephone questionnaires. Results: Teachers most often made minor curriculum changes, and they added/subtracted student assessments (primarily informal assessments) least often. Self-initiated (bottom-up) change was most frequently (83.1% of the time) reported. Externally initiated (top-down) changes were less frequent and were most often associated with professional development. Teachers reported principals' involvement in both top-down and bottom-up change processes was minimal. Teachers who were more disposed to making future changes reported making significantly (p < 0.01, ?[superscript 2] = 0.046-0.119) more past changes than those who were less disposed to change. Conclusions: Physical education teachers primarily self-initiated minor programming changes without involvement from administration. Externally initiated change was infrequent and mostly involved professional development. Dispositions toward change were individual and enduring such that teachers who had made more past changes were more likely to also make future changes.