Persuasive writing is a powerful, pervasive form of social communication that is also frequently demanded on the high-stakes tests that characterize standards-based education. This article explores the question, "How can I help students get better at persuasive writing on tests without sacrificing what I value about writing workshop?" A third and a fourth grade classroom are the sites for an investigation of how the teachers’ writing-process-based instruction influences the quality of students’ persuasive writing to test-like prompts. Results point to a number of suggestions for teachers interested in teaching persuasive writing in a principled way while also preparing students for high-stakes tests.