This pilot randomized controlled trial evaluated the preliminary effects of the online EMDR Flash Group Protocol among adults affected by the 2023 Kahramanmaraş earthquakes in Türkiye. Participants were randomly assigned to either the EMDR Flash Group Protocol or a waitlist control group. The primary outcome was change in posttraumatic stress symptoms measured by the PTSD Checklist for DSM-5 (PCL-5). Secondary outcomes included depression, anxiety, and stress symptoms measured by the Depression Anxiety Stress Scale-21 (DASS-21). Outcomes were assessed at baseline and at 3-month follow-up.