Brush cytology is complementary to endoscopic biopsy and is recommended by some to be part of the routine endoscopic surveillance of patients with BE. Advantages of cytology include the ability to sample a greater area of involved epithelium, preferential exfoliation of the less cohesive dysplastic cells, simplicity, and lower cost. There are clear cytologic criteria for dysplasia, and biomarker studies can be performed on cytologic specimens. Despite these advantages, cytology is used by only 17% of gastroenterologists in the United States today. Limited data are available on the usefulness of cytology in the diagnosis and surveillance of BE. Cytology has good sensitivity for the detection of adenocarcinoma and HGD and good specificity for the detection of IM without dysplasia. Furthermore, cytology may detect abnormalities missed by biopsy. Cytology has problems in the detection of LGD, however. For cytology to become a useful surveillance option, its sensitivity for low-grade lesions must be improved. One potential way to accomplish this is to add biomarkers to routine cytologic specimens to define patients at increased risk of progression to cancer. If simple prognostic biomarkers could be developed and validated in histology and cytologic specimens, this would provide additional support for the utility of cytologic brushings in the surveillance of BE. Cytology could then conceivably accomplish the goals of improved efficiency, risk stratification, and decreased costs in BE surveillance programs.