The aim of this study was to investigate the effectiveness of explicit, structured strategybased procedural facilitation in writing, fostering cognitive apprenticeship and selfregulation strategies, (Bereiter, and Scardamalia, 1987, Spantidakis, 2010) along with its effects on the anxiety levels of fifth and sixth grade English language learners studying at a mainstream primary school in Chania, Crete, Greece. Specifically, the current study examined whether structured instruction in writing and self-regulation strategies, guided by strategy-based procedural facilitation in writing, would result in the improvement of students' writing quality, metacognitive knowledge, metacognitive skills, and metacognitive behavior as well as whether there would be a reduction in the students' anxiety levels. The participants consisted of one hundred and seventy seven (177) grade five (5), and six (6) primary school students. One hundred (100) students were part of the control group and seventy-seven (77) were part of the research group. The subjects were identified as below average, average, and above average writers and were randomly assigned into two treatment groups; the experimental group was provided with strategybased procedural facilitation for two writing genres: story writing, and expository essay, and the control group that did not receive any writing instruction whatsoever, apart from the guidelines outlined by the Greek Ministry of Education. Participants' first language (L1) writing samples were also collected on both story writing and expository essays from the control and the experimental group, so as to investigate possible transfer of strategies from L2 to L1. The data collection included (a) pre and post-test foreign language writing samples on both story writing and expository essay; (b) semi-structured individual interviews; (c) participant observation; (d) anxiety questionnaires; (e) writing samples on first language (L1). Statistical important differences in scores between pretest and post-test indicated that students' writing products improved in terms of overall writing quality; students' metacognitive knowledge, metacognitive skills and in turn metacognitive behavior was enhanced, while feelings of anxiety lessened.