The purpose of this study was to evaluate the effects of a curriculum for college developmental writing classes, developed in prior design research and based on self-regulated strategy instruction. Students learned strategies for planning, drafting, and revising compositions with an emphasis on using knowledge of genre organization to guide planning and self-evaluation. In addition to specific writing strategies, students learned strategies for self-regulation. This quasi-experimental study involved 13 instructors and 276 students in 19 developmental writing classes at 2 universities. The curriculum was taught for a full semester in 9 classes and compared with a business-as-usual control condition in 10 classes. Significant positive effects were found for overall quality of writing on a persuasive essay (ES = 1.22), and for length (ES = 0.71), but not for grammar. Significant positive effects were also found for self-efficacy and mastery motivation.