BACKGROUND Prevalence of oral cancer is high in Sudan and the disease is attributed to N-nitrosamine rich oral snuff consumption. MATERIALS AND METHODS As part of the development of a screening procedure for oral cancer and precancer, exfoliative cytology (EFC) was applied to a retrospective cohort to assess the presence and severity of oral epithelial atypia (ET) in 300 subjects (100 toombak dippers; 100 cigarette smokers; 100 non-tobacco users) without prior knowledge of the subjects' tobacco exposure. Five patients with oral squamous cell carcinoma (OSCC) were included as internal controls. RESULTS ET was ascertained in 29 subjects and could not be ascertained in the remaining 271. Among the 29 subjects with ET, there were 11 (38%) toombak dippers, 14 (48%) cigarette smokers and 4 (14%) non-tobacco users. Among the 271 subjects without ET, there were 89 (33%) toombak dippers, 86 (32%) cigarette smokers and 96 (35%) non-tobacco users. ET was found in all the 5 control cases with OSCC. For the ET among toombak dippers and cigarette smokers, adjusted OR and the 95% CI were found to be 3 (0.91-9.7) and 4 (1.2-12.3), respectively. CONCLUSION In view of these findings, we propose the use of EFC for detection and assessment of oral ET.