Twenty teachers working in elementary and secondary schools were interviewed from 2 school districts in southern Ontario, Canada about their understanding and use of particular formative assessment strategies. Analysis of the interviews followed a constant comparison method and revealed a variety of emerging themes. Results suggested an imbalance in the use of formative assessment methods associated with improvements in student learning and achievement. Many teachers noted tensions in utilizing particular formative assessment strategies such as peer assessment and self-assessment. The discussion focuses on the implications for teacher education reform and in-service professional development so that greater synergy between formative assessment research and practice can be obtained in contemporary classrooms.