Although it is widely agreed that teacher sensitivity to individual learning differences (ILDs) is an integral component of effective teaching, little research has focused on how to develop this sensitivity in teachers. This study describes the reported effects of a year-long professional development course designed to sensitize 14 teachers to their own and their colleagues' learning differences. The teachers explored their own ILDs in a mediated context with colleagues, utilizing a battery of learning styles inventories. In order to document any teacher change as a result of the course, the researchers collected data from interviews, written critical incidents, questionnaire, and field notes. A taxonomy of teacher change in language, beliefs and practice was constructed from the data using qualitative research analysis. Teachers reported the following changes: gaining a fluency in the language of individual learning differences; gaining interventionist beliefs about students; increased legitimizing and addressing of individual learning differences; and positive outcomes as a result of their changes, that is, awareness of self-development and increased learner success. An empirical model of developing teacher sensitivity to ILDs is presented, with implications for teacher professional development.