Purpose of Review <p>This narrative review investigates predictors of treatment response to Non-Invasive Brain Stimulation (NIBS) techniques in obsessive-compulsive disorder (OCD).</p> Recent Findings <p>Non-invasive brain stimulation (NIBS) techniques hold promise for treating OCD, but success can depend on several factors. For repetitive magnetic stimulation (rTMS) and deep TMS (dTMS), targeting specific brain regions like the DLPFC and mPFC appears crucial. Additionally, illness severity in rTMS and age with OCD severity in dTMS influence response. Interestingly, tDCS might benefit from stimulation location, with cathodal stimulation on the pre-SMA or left OFC showing potential. Even brain connectivity seems to play a role, as tDCS responders may exhibit increased connectivity within specific circuits. In essence, both the chosen NIBS technique and a patient’s individual characteristics seem to influence treatment outcomes in OCD, highlighting the need for personalized treatment approaches.</p> Summary <p>Multiple NIBS techniques show promise for treating OCD, but factors influencing response vary across each method. For rTMS and dTMS, stimulation targeting specific brain regions appears important. Additionally, illness severity and specific patient characteristics seem to influence treatment outcomes. Further research is needed to solidify the role of tACS and ECT in OCD treatment and to explore a wider range of predictors for all NIBS techniques to optimize treatment personalization.</p>