Oral and pharyngeal cancer is the sixth most common cancer worldwide, the 5-year survival rate has not yet increased. A key factor in rates not having improved is the lack of early detection. This study was undertaken to estimate the diagnostic accuracy of brush biopsy with DNA-image cytometry (a noninvasive method) for potentially malignant oral disorders compared with tissue biopsy pathology in China. Exfoliative cells were obtained using a cytobrush cell collector from oral mucosa of 52 subjects, followed by scalpel biopsy from the same region. Nuclear DNA contents (ploidy) were measured after Feulgen restaining, using an automated DNA image cytometer. Exfoliative cytology with DNA-image cytometry and histopathological diagnosis were performed separately at different institutions. Histological investigation was considered the gold standard. We reported that the sensitivity of DNA aneuploidy for the detection of cancer cells in potentially malignant oral disorders was 86.36 %, its specificity was 90.00 %, its positive predictive value was 86.36 %, and its negative predictive value was 90.00 %. Brush biopsy with DNA-image cytometry is a useful method for monitoring potentially malignant oral disorders.