Writing is a critical tool for developing thinking and communicating ideas. However, only about a third of students across grades 4, 8 and 12 meet standards for proficient writing (NCES, 2011). While writing generally has long been a neglected area of curricula, this is especially the case with argument writing. The proposed presentation describes a three-week intervention to teach argument writing to middle school students and reports results of a pilot test of its implementation. Results on a pre/post argument writing assessment task showed significant growth in argument writing for both sixth and seventh graders. Areas of growth and of remaining difficulty with the argument genre will be discussed.