Dialogic peer feedback has been recommended and increasingly used in English as a foreign language writing context, yet the specific effects of peer-to-peer written dialogue about feedback remain under-researched. Using a quasi-experimental design, this empirical study investigated the effects of the presence/absence of written dialogue between the peer feedback provider and receiver on students' provision of feedback, adoption of received feedback, improvements in writing quality, and attitudes towards feedback dialogue across a four-week writing program. The study drew on several data sources including feedback texts, revision texts, a questionnaire survey and monthly reflection journals of forty-one students. Results showed that students involved in the written dialogue demonstrated a generally positive attitude towards it and outperformed those without such a process by generating more accurate adoption, focusing comments to a greater extent on higher-order dimensions of writing (unity, support and coherence), and implementing better revisions. The dialogic process enhanced students' feedback literacy and engagement by improving their understanding of feedback, their linguistic and subject knowledge, and their agentic clarification and negotiation of revisions.