BACKGROUND: Sickle cell anemia (SCA) is an autosomal recessive genetic disorder, characterized by chronic hemolytic anemia, episodic painful crises, and pathologic involvement of many organs, consequence of vaso occlusive phenomenon and vasculopathy. Several forms of the chronic anemia, consequence of hemolysis, can be associated with oral epithelial cells changes. Exfoliative cytology can be used to detect real changes in the oral mucosa in SCA. AIMS: To evaluate morphometric and morphological changes in oral epithelial cells by exfoliative cytology in children with SCA. MATERIALS AND METHODS: Oral smears were collected from clinically normal-appearing mucosa by liquid-based exfoliative cytology in 20 SCA children (SCA group) and 20 healthy children (C group), matched for age and gender. The slides were prepared and stained by the Papanicolaou technique. Cell morphology and cellularity were analyzed and compared by Chi-square test (P < 0.05). Images of 50 cells per slide were captured and the nuclear area (NA) and cytoplasmic area (CA) were analyzed using an image analysis system. The nucleus-to-cytoplasmic area ratio (NA/CA) was calculated. To compare the means of groups SCA and C, the Student's t-test (P < 0.05) was applied to NA and CA; test non-parametric Mann Whitney U (P < 0.05) was used to compare NA/CA. RESULTS: MEAN VALUES FOR SCA AND C GROUPS WERE: NA (69.38 and 59.63 µm²; P = 0.01); CA (2321.85 and 2185.60 µm²; P = 0.24); NA/CA (0.03 and 0.02; P = 0.13), respectively. A significant increase in NA for SCA group (P = 0.01) was seen. No morphological differences were found between the groups. There was a predominance of nucleated cells of the superficial layer in the smears of both groups. Class I smears were predominant in both groups. CONCLUSIONS: This study revealed that SCA was able to induce significant changes on nuclear area of the oral epithelial cells.