This study explores the reasons why teachers introduce innovations into their teaching. Interviews were conducted with thirty teachers in primary, secondary, and university settings in one Midwestern USA community. All participants said they innovated due to a desire to improve student learning; other frequently mentioned reasons were professional development experiences of their own choosing and a desire to avoid personal boredom. Less frequently stated reasons to innovate included the failure of textbooks and experiences with another teacher or the participants' own children. Implications for professional development include encouraging teachers to discover innovations applicable to their own classrooms through providing them with time and autonomy to develop alternative approaches to teaching curriculum.