Feulgen DNA content and nuclear area were determined for both normal and pathologic oral squames to assess the diagnostic potential of nuclear area determination. In the normal specimens, Feulgen DNA content was consistent with observations made in a nonreplicating cell population. Variation in individual mean nuclear area among the sample of 20 normal patients was not statistically significant. The overall mean nuclear area for this group was calculated and used as a baseline against which the abnormal tissue could be compared. Abnormal DNA profiles were detected in carcinomas and in a case showing mild epithelial atypia. Nuclear area was increased significantly in malignant lesions but was also elevated in lesions showing no malignancy. It is concluded that the determination of nuclear area has, at the present, no specific diagnostic value since there appeared to be no clear relationship between nuclear area, DNA content, clinical presentation and histopathology in abnormal cases.