AIM: To determine if a new brush design could im-prove the diagnostic yield of biliary stricture brushings. METHODS: Retrospective chart review was performed of all endoscopic retrograde cholangiopancreatography procedures with malignant biliary stricture brushing between January 2008 and October 2012. A standard wire-guided cytology brush was used prior to proto-col implementation in July 2011, after which, a new 9 French wire-guided cytology brush(Infinity sampling device, US Endoscopy, Mentor, OH) was used for all cases. All specimens were reviewed by blinded pa-thologists who determined whether the sample waspositive or negative for malignancy. Cellular yield was quantified by describing the number of cell clusters seen. RESULTS: Thirty-two new brush cases were compared to 46 historical controls. Twenty-five of 32 (78%) cases in the new brush group showed abnormal cellular find-ings consistent with malignancy as compared to 17 of 46(37%) in the historical control group(P = 0.0003). There was also a significant increase in the average number of cell clusters of all sizes(21.1 vs 9.9 clusters, P = 0.0007) in the new brush group compared to his-torical controls. CONCLUSION: The use of a new brush design for brush cytology of biliary strictures shows increased di-agnostic accuracy, likely due to improved cellular yield, as evidenced by an increase in number of cellular clus-ters obtained. METHODS: Retrospective chart review was performed of all endoscopic retrograde cholangiopancreatography procedures with malignant biliary stricture brushing between January 2008 and October 2012. A standard wire- guided cytology brush was used prior to proto-col implementation in July 2011, after which, a new 9 French wire-guided cytology brush (Infinity sampling device, US Endoscopy, Mentor, OH) was used for all cases. blinded pa-thologists who determined whether the sample waspositive or negative for malignancy. Cellular yield was quantified by describing the number of cell clusters seen. RESULTS: Thirty-two new brush cases were compared to 46 historical controls. Twenty-five of 32 %) cases in the new brush group showed abnormal cellular find -ings consistent with malignancy as compared to 17 of 46 (37%) in the historical control group (P = 0.0003). There was also a significant increase in the average number of cell clusters of all sizes (21.1 vs 9.9 clusters, P = 0.0007) in the new brush group compared to his-torical controls. CONCLUSION: The use of a new brush design for brush cytology of biliary strictures shows increased di-agnostic accuracy, likely due to improved cellular yield, as evidenced by an increase in number of cellular clustering.