Objective. To determine if oral lesions exhibiting bowenoid features reflect the diverse microscopic appearance and biologic behaviour of Bowen’s disease and bowenoid papulosis of the skin and genitalia. Study Design. Seven cases of oral bowenoid lesions (6 with follow-up data) were assessed for differences in histologic features, human papillomavirus (HPV) viral status, and selected immunohistochemically detectable cell cycling proteins (p53, WAF-1, Cyclin D1, Bcl-2) and were correlated with available follow-up data. Results. Two histologic subsets were identified. One, which was believed to correspond to Bowen’s disease, exhibited large numbers of transepithelial apoptotic bodies, dyskeratotic cells and mitoses (bowenoid elements), poor differentiation of background epithelial cells, and consistent HPV-16/18 positivity. The other, believed to correspond to bowenoid papulosis, exhibited few bowenoid elements, good background differentiation, and inconsistent HPV-16/18 positivity. One of the aggressive cases exhibited repeated recurrences despite apparent total clinical excision, whereas none of the other group recurred. Conclusion. Although a small number of cases are in this study, results suggest that oral bowenoid lesions may exhibit histopathologic and behavioral variations ranging from oral Bowen’s disease to oral bowenoid papulosis. Studies on more cases are needed to confirm this initial impression. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000;90:466-73)