Background and aims <p>Pathological evaluation is crucial for diagnosing biliary strictures. This study aimed to evaluate the diagnostic efficacy and safety of peroral cholangioscopy combined with modified biopsy forceps for malignant biliary strictures.</p> Methods <p>We retrospectively collected data from inpatients with suspected extrahepatic malignant biliary strictures who underwent peroral cholangioscopy at Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, and The First Affiliated Hospital of Shihezi University from January 2020 to March 2025. The experimental group used peroral cholangioscopy combined with modified biopsy forceps, and the control group used peroral cholangioscopy. We compared the diagnostic efficacy and safety of the two biopsy methods.</p> Results <p>A total of 158 patients were included in the study, with 79 patients each in the experimental group and the control group. The detection rate of carcinoma in situ (high-grade intraepithelial neoplasia/severe dysplasia) was significantly higher in the experimental group than in the control group (32.9% vs 6.3%, <i>P</i> &lt; 0.001). Regarding diagnostic efficacy and safety, the accuracy (93.7% vs 72.2%, <i>P</i> &lt; 0.001), sensitivity (93.2% vs 71.4%, <i>P</i> &lt; 0.001), negative predictive value (50.0% vs 8.3%, <i>P</i> = 0.014) and negative likelihood ratio (0.068 vs 0.286)&#xa0;of the experimental group were significantly superior to those of the control group. There was no significant difference between the two groups in terms of specificity (100.0% vs 100.0%, <i>P</i> = 1.000), positive predictive value (100.0% vs 100.0%, <i>P</i> = 1.000), or the incidence of adverse events (7.6% vs 8.9%, <i>P</i> = 1.000).</p> Conclusions <p>Compared with POCS-guided biopsy using dedicated forceps, peroral cholangioscopy combined with modified biopsy forceps demonstrates higher diagnostic efficacy for malignant biliary strictures and maintains a good safety profile.</p> Graphical abstract <p></p>