Thisstudy aimed to investigatethe efficacy of γ-tACS in reducing compulsive checking symptoms in patients with obsessive–compulsive disorder(OCD).Considering theresistance of some patients to conventional pharmacological and psychotherapeutic treatments, the use of neuromodulation techniques mayprovide a novel and effective approach for managing these symptoms.This study was anapplied, semi-experimental design witha pretest–posttest structure and acontrol group.Thesample consisted of 14 patients(11 females and 3 males),randomly assigned to an experimental group (n=7) and a control group (n=7). The experimental group received 10 sessions of real γ-tACS at 40 Hz, 1.5 mA intensity, for 20 minutes per session, with the anode placed over F4 and the cathode over P4; the control group received no intervention.Assessment tools included theYale–Brown Obsessive–CompulsiveScale(Y-BOCS)andthechecking subscale of the Padua Inventory(PI).Data were analyzed using analysis of covariance(ANCOVA) in SPSS version 26. The experimental group showed a significant reduction compared to the control group in the checking subscale of the PI (F(1,11)=11.301, p=0.005, η²=0.643) and total Y-BOCS scores (F(1,11)=12.001, p<0.001, η²=0.678). Moreover, 71.4% of participants in the experimental group were identified as treatment responders.The findings indicated that gamma-frequency tACS over the right frontoparietal region could serve as a safe, tolerable and effective adjunctive intervention for reducing compulsive checking symptoms, particularly in treatment-resistant OCD patients.