How to prepare teachers to be effective in our nations' classrooms seems to get increasingly complex, yet the links between teacher education and teachers' eventual practices are little understood. Using complexity theory as a theoretical framework, this mixed-methods study investigated writing teacher practices of 23 elementary teachers. Twelve teachers had participated in a comprehensive course focused on writing, either at inservice or preservice levels. The other teachers had not taken any course focused on writing and had little to no writing professional development. Despite the small number of participants in our study, quantitative analysis demonstrated significant differences on multiple, effective practice indicators. These findings were borne out in qualitative analyses as well. Clear connections of teachers' practices and understandings and the course were noted. These findings contribute to understandings of the ways in which teacher education coursework makes a difference in optimizing candidate learning and reducing the variability across teacher practices and subsequent student learning opportunities. Findings suggest implications for policy makers, teacher education programs, as well as for teacher educators and researchers.